View source for Help:Parser functions

{{Construction}}
'''Parser functions''' are very similar to [[Help:Magic words#General_information|variables]] but take one or more parameters (technically, any magic word that takes a parameter is a parser function), and the name is sometimes prefixed with a [[wikipedia:Number sign|hash]] to distinguish them from templates. In addition to the parser functions included with MediaWiki the [[mw:Extension:ParserFunctions|ParserFunctions extension]] installed here adds more.

Parser functions marked as "<span class="table-bg-orange ">[expensive]</span>" are tracked by the software, and the number that can be included on a page is limited (stacks with "<span class="table-bg-orange ">[expensive]</span>" [[Help:Magic words|magic words]]).

==Basic==
===Technical metadata of another page===
{| class="wikitable"
|-
! width="15%" | Parser function
! width="10%" | Output<br />(for page [[Eris Ice]])
! Description
|- class="table-bg-orange"
| <code><nowiki>{{PAGEID: </nowiki>''page name''<nowiki> }}</nowiki></code>
| {{PAGEID: Eris Ice }}
| '''[Expensive]''' Returns the page identifier of the specified page*.
|- class="table-bg-orange"
| {{Anchor|PAGESIZE:|PAGESIZE}}<code><nowiki>{{PAGESIZE:</nowiki> ''page name''<nowiki>}}</nowiki></code> <br /><code><nowiki>{{PAGESIZE: </nowiki>''page name''<nowiki> |R}}</nowiki></code>
| {{PAGESIZE: Cow }} <br />{{PAGESIZE: Eris Ice |R}}
| '''[Expensive]''' Returns the byte size of the specified page. Use "<code><nowiki>|R</nowiki></code>" to get raw (unformatted) numbers.
|- class="table-bg-orange"
| {{Anchor|PROTECTIONLEVEL:}}<code><nowiki>{{</nowiki>PROTECTIONLEVEL:
''action'' &#124;
''page name''}}</code>
| {{PROTECTIONLEVEL: edit | Eris Ice }}
| '''[Expensive]''' Outputs the protection level (e.g. "autoconfirmed", "sysop") for a given action (e.g. "edit", "move") on the specified page. Returns an empty string if not protected.
|- class="table-bg-orange"
| {{Anchor|PROTECTIONEXPIRY:}}<code><nowiki>{{</nowiki>PROTECTIONEXPIRY:
''action'' &#124;
''page name''}}</code>
| {{PROTECTIONEXPIRY: edit | Eris Ice }}
| '''[Expensive]''' Outputs the protection expiry (e.g. "20160418155030", "infinity") for a given action (e.g. "edit", "move") on the specified page. Returns "infinity" if not protected.
|- class="table-bg-orange"
| {{Anchor|CASCADINGSOURCES:}}<code><nowiki>{{CASCADINGSOURCES:</nowiki> ''page name''<nowiki>}}</nowiki></code>
| 
| '''[Expensive]''' Returns the sources of any cascading protection acting on the specified page. Pages will not return their own title unless they transclude themselves.
|- class="table-bg-orange"
| {{Anchor|REVISIONID:}}<code><nowiki>{{REVISIONID: </nowiki>''page name''<nowiki> }}</nowiki></code>
| {{REVISIONID: Eris Ice }}
| '''[Expensive]''' Unique revision ID of the last revision on the specified page*.
|- class="table-bg-orange"
| {{Anchor|REVISIONDAY:}}<code><nowiki>{{REVISIONDAY: </nowiki>''page name''<nowiki> }}</nowiki></code>
| {{REVISIONDAY: Eris Ice }}
| '''[Expensive]''' Day of edit from the last revision of the specified page* (unpadded number).
|- class="table-bg-orange"
| {{Anchor|REVISIONDAY2:}}<code><nowiki>{{REVISIONDAY2: </nowiki>''page name''<nowiki> }}</nowiki></code>
| {{REVISIONDAY2: Eris Ice }}
| '''[Expensive]''' Day of edit from the last revision of the specified page* (zero-padded number).
|- class="table-bg-orange"
| {{Anchor|REVISIONMONTH:}}<code><nowiki>{{REVISIONMONTH: </nowiki>''page name''<nowiki> }}</nowiki></code>
| {{REVISIONMONTH: Eris Ice }}
| '''[Expensive]''' Month of edit from the last revision of the specified page* (zero-padded number ).
|- class="table-bg-orange"
| {{Anchor|REVISIONMONTH1:}}<code><nowiki>{{REVISIONMONTH1: </nowiki>''page name''<nowiki> }}</nowiki></code>
| {{REVISIONMONTH1: Eris Ice }}
| '''[Expensive]''' Month of edit from the last revision of the specified page* (unpadded number).
|- class="table-bg-orange"
| {{Anchor|REVISIONYEAR:}}<code><nowiki>{{REVISIONYEAR: </nowiki>''page name''<nowiki> }}</nowiki></code>
| {{REVISIONYEAR: Eris Ice }}
| '''[Expensive]''' Year of edit from the last revision of the specified page*.
|- class="table-bg-orange"
| {{Anchor|REVISIONTIMESTAMP:}}<code><nowiki>{{REVISIONTIMESTAMP: </nowiki>''page name''<nowiki> }}</nowiki></code>
| {{REVISIONTIMESTAMP: Eris Ice }}
| '''[Expensive]''' Timestamp as of time of edit on the specified page*.
|- class="table-bg-orange"
| {{Anchor|REVISIONUSER:}}<code><nowiki>{{REVISIONUSER: </nowiki>''page name''<nowiki> }}</nowiki></code>
| {{REVISIONUSER: Eris Ice }}
| '''[Expensive]''' The username from the last revision on the specified page*.
|-
| colspan="3" |
*When the given param is equal to the current title of the parser, the parser function will yield the previous versions on preview and on substitution, that includes empty strings when used on page creation but using the values from the current version for page view, including viewing old revisions. In this case it is a non-expensive parser function.
|}

===URL data===
{|class="wikitable"
|-
!scope="col"| Parser function
!scope="col"| Input → Output
!scope="col"| Description
|-
|colspan="3"| {{Anchor|localurl|LOCALURL}}
|-
| <code><nowiki>{{localurl:</nowiki>''page name''<nowiki>}}</nowiki></code> <br /><code><nowiki>{{localurl:</nowiki>''page name''<br /><nowiki>|</nowiki>''query_string''<nowiki>}}</nowiki></code>
| <code><nowiki>{{localurl:Cow}}</nowiki></code><br />→ {{localurl:Eris Ice}} <br /><code><nowiki>{{localurl:Cow|printable=yes}}</nowiki></code><br />→ {{localurl:Eris Ice|printable=yes}}
| The relative path to the title.
|-
|colspan="3"| {{Anchor|fullurl|FULLURL}}
|-
| <code><nowiki>{{fullurl:</nowiki>''page name''<nowiki>}}</nowiki></code> <br /><code><nowiki>{{fullurl:</nowiki>''page name''<br /><nowiki>|</nowiki>''query_string''<nowiki>}}</nowiki></code> <br /><code><nowiki>{{fullurl:</nowiki>''interwiki:remote page name''<br /><nowiki>|</nowiki>''query_string''<nowiki>}}</nowiki></code>
| <code><nowiki>{{fullurl:Category:Non-player characters}}</nowiki></code><br />→ {{fullurl:Category:Non-player characters}} <br />
<code><nowiki>{{fullurl:Category:Non-player characters|action=edit}}</nowiki></code><br />→ {{fullurl:Category:Non-player characters|action=edit}}<br />
<code><nowiki>{{fullurl:ptrsw:Vaca|action=edit}}</nowiki></code><br />→ {{fullurl:ptrsw:Vaca|action=edit}}<br />
<code><nowiki>{{fullurl:ptrsw:Categoria:Monstros|action=edit}}</nowiki></code><br />→ {{fullurl:ptrsw:Categoria:Monstros|action=edit}}
| A protocol-relative path to the title, which depends on the [[mw:Manual:$wgServer|$wgServer]] configuration setting for the local wiki (and so may or may not start with <code>http(s)://</code>). This will also resolve [[Help:Interlanguage links|interwiki]] prefixes. '''Note:''' Unbracketed (plain) protocol-relative links are not automagically linked.
|-
|colspan="3"| {{Anchor|canonicalurl|CANONICALURL}}
|-
| <code><nowiki>{{canonicalurl:</nowiki>''page name''<nowiki>}}</nowiki></code> <br /><code><nowiki>{{canonicalurl:</nowiki>''page name''<br /><nowiki>|</nowiki>''query_string''<nowiki>}}</nowiki></code> <br /><code><nowiki>{{canonicalurl:</nowiki>''interwiki:remote page name''<br /><nowiki>|</nowiki>''query_string''<nowiki>}}</nowiki></code>
| <code><nowiki>{{canonicalurl:Category:Non-player characters}}</nowiki></code><br />→ {{canonicalurl:Category:Non-player characters}} <br />
<code><nowiki>{{canonicalurl:Category:Non-player characters|action=edit}}</nowiki></code><br />→ {{canonicalurl:Category:Non-player characters|action=edit}}
| The absolute path to the title, using the canonical URL. This will also resolve [[Help:Interlanguage links|interwiki]] prefixes.
|-
|colspan="4"| {{Anchor|filepath|FILEPATH}}
|-
| <code><nowiki>{{filepath:</nowiki>''file name''<nowiki>}}</nowiki></code> <br /><code><nowiki>{{filepath:</nowiki>''file name''<nowiki>|nowiki}}</nowiki></code> <br /><code><nowiki>{{filepath:</nowiki>''file name''<nowiki>|</nowiki>''thumbnail_size'<nowiki>}}</nowiki></code>
| <code><nowiki>{{filepath:Eris Ice.png}}</nowiki></code><br />→ {{filepath:Eris Ice.png}} <br />
<code><nowiki>{{filepath:Eris Ice.png|nowiki}}</nowiki></code><br />→ {{filepath:Eris Ice.png|nowiki}} <br />
<code><nowiki>{{filepath:Eris Ice.png|300}}</nowiki></code><br />→ {{filepath:Eris Ice.png|300}} <br /><br />
The parameter <code>nowiki</code> usually removes the link around the filepath (which can't be seen in this example).
| A protocol-relative path to the full size or thumbnail of a media file.
|-
|colspan="3"| {{Anchor|urlencode|URLENCODE}}
|-
| <code><nowiki>{{urlencode:</nowiki>''string''<nowiki>}}</nowiki></code> or <br /><code><nowiki>{{urlencode:</nowiki>''string''<nowiki>|QUERY}}</nowiki></code> <br /><code><nowiki>{{urlencode:</nowiki>''string''<nowiki>|WIKI}}</nowiki></code> <br /><code><nowiki>{{urlencode:</nowiki>''string''<nowiki>|PATH}}</nowiki></code>
| <code><nowiki>{{urlencode:x:y/z á é}}</nowiki></code> or <br /><code><nowiki>{{urlencode:x:y/z á é|QUERY}}</nowiki></code><br />→ {{urlencode:x:y/z á é}} <br /><code><nowiki>{{urlencode:x:y/z á é|WIKI}}</nowiki></code><br />→ {{urlencode:x:y/z á é|WIKI}} <br /><code><nowiki>{{urlencode:x:y/z á é|PATH}}</nowiki></code><br />→ {{urlencode:x:y/z á é|PATH}}
Note that the default is <code>|QUERY</code>.
| The input encoded for use in URLs. Note that there is no urldecode function like there is in the obsolete [[mw:Extension:StringFunctions|StringFunctions extension]].<br /><table class="wikitable"><caption>Encoding</caption><tr><th>code</th><th>space</th></tr><tr><td>&nbsp;''none''</td><td><samp>&nbsp;+&nbsp;</samp></td></tr><tr><td><kbd>QUERY</kbd></td><td><samp>&nbsp;+&nbsp;</samp></td></tr><tr><td><kbd>&nbsp;WIKI</kbd></td><td><samp>&nbsp;_&nbsp;</samp></td></tr><tr><td><kbd>&nbsp;PATH</kbd></td><td><samp>%20</samp></td></tr></table>
|-
|colspan="3"| {{Anchor|anchorencode|ANCHORENCODE}}
|-
| <code><nowiki>{{anchorencode:</nowiki>''string''<nowiki>}}</nowiki></code>
| <code><nowiki>{{anchorencode:x y z á é}}</nowiki></code><br />→ {{anchorencode:x y z á é}}
| The input encoded for use in URL section anchors (after the “#” symbol in a URL).
|}

===Namespaces===
<code><nowiki>{{ns:}}</nowiki></code> returns the current localized name for the [[Help:Namespace|namespace]] with that index, canonical name, or local alias. Thus <code><nowiki>{{ns:6}}</nowiki></code>, <code><nowiki>{{ns:File}}</nowiki></code>, and <code><nowiki>{{ns:Image}}</nowiki></code> (an old name for the File namespace) all return "{{ns:6}}". On a wiki where the content language is French, <code><nowiki>{{ns:Fichier}}</nowiki></code></> is also valid, but ><code><nowiki>{{ns:Datei}}</nowiki></code> (the localisation of "File" in German) is not.

<code><nowiki>{{nse:}}</nowiki></code> is the equivalent encoded for MediaWiki URLs. It does the same, but it replaces spaces with underscores, making it usable in external links.

Standard namespaces:
{| class="wikitable"
|-
! colspan="2" width="50%" | Content namespaces
! rowspan="11" |
! colspan="2" width=%50%" | Talk namespaces
|-
! Usage
! Output
! Usage
! Output
|-
| <code><nowiki>{{ns:-2}}</nowiki></code> / <code><nowiki>{{ns:Media}}</nowiki></code>
| {{ns:-2}} 
| <code><nowiki>{{ns:-1}}</nowiki></code> / <code><nowiki>{{ns:Special}}</nowiki></code>
| {{ns:-1}}<br/>''(no '''talk''' page)''
|-
| <code><nowiki>{{ns:0}}</nowiki></code> / <code><nowiki>{{ns:}}</nowiki></code>
| {{ns:0}}
| <code><nowiki>{{ns:1}}</nowiki></code> / <code><nowiki>{{ns:Talk}}</nowiki></code>
| {{ns:1}}
|-
| <code><nowiki>{{ns:2}}</nowiki></code> / <code><nowiki>{{ns:User}}</nowiki></code>
| {{ns:2}}
| <code><nowiki>{{ns:3}}</nowiki></code> / <code><nowiki>{{ns:User talk}}</nowiki></code>
| {{ns:3}}
|-
| <code><nowiki>{{ns:4}}</nowiki></code> / <code><nowiki>{{ns:Project}}</nowiki></code>
| {{ns:4}} <br/>''Varies between wikis''
| <code><nowiki>{{ns:5}}</nowiki></code> / <code><nowiki>{{ns:Project talk}}</nowiki></code>
| {{ns:5}}
|-
| <code><nowiki>{{ns:6}}</nowiki></code> / <code><nowiki>{{ns:File}}</nowiki></code> or <code><nowiki>{{ns:Image}}</nowiki></code>
| {{ns:6}}
| <code><nowiki>{{ns:7}}</nowiki></code> / <code><nowiki>{{ns:File talk}}</nowiki></code> or <code><nowiki>{{ns:Image talk}}</nowiki></code>
| {{ns:7}}
|-
| <code><nowiki>{{ns:8}}</nowiki></code> / <code><nowiki>{{ns:MediaWiki}}</nowiki></code>
| {{ns:8}}
| <code><nowiki>{{ns:9}}</nowiki></code> / <code><nowiki>{{ns:MediaWiki talk}}</nowiki></code>
| {{ns:9}}
|-
| <code><nowiki>{{ns:10}}</nowiki></code> / <code><nowiki>{{ns:Template}}</nowiki></code>
| {{ns:10}}
| <code><nowiki>{{ns:11}}</nowiki></code> / <code><nowiki>{{ns:Template talk}}</nowiki></code>
| {{ns:11}}
|-
| <code><nowiki>{{ns:12}}</nowiki></code> / <code><nowiki>{{ns:Help}}</nowiki></code>
| {{ns:12}}
| <code><nowiki>{{ns:13}}</nowiki></code> / <code><nowiki>{{ns:Help talk}}</nowiki></code>
| {{ns:13}}
|-
| <code><nowiki>{{ns:14}}</nowiki></code> / <code><nowiki>{{ns:Category}}</nowiki></code>
| {{ns:14}}
| <code><nowiki>{{ns:15}}</nowiki></code> / <code><nowiki>{{ns:Category talk}}</nowiki></code>
| {{ns:15}}
|}
Don't confuse localised namespaces with custom namespaces.

===Formatting===
{| class="wikitable"
! width="10%" | Usage
! width="40%" | Input → Output
! Description
|-
| <code><nowiki>{{formatnum:</nowiki>''unformatted number''<nowiki>}}</nowiki></code> <br />
<code><nowiki>{{formatnum:</nowiki>''formatnum-formatted&nbsp;number''<nowiki>|R}}</nowiki></code> <br />
<code><nowiki>{{formatnum:</nowiki>''unformatted number''<nowiki>|NOSEP}}</nowiki></code>
| 
* Simple:
** <code><nowiki>{{formatnum:987654321.654321}}</nowiki></code> <br/> → {{formatnum:987654321.654321}}
** <code><nowiki>{{formatnum:</nowiki>{{formatnum:987654321.654321}}<nowiki>|R}}</nowiki></code> <br/> → {{formatnum:{{formatnum:987654321.654321}}|R}}
* Advanced:
** <code><nowiki>{{formatnum:{{formatnum:987654321.654321}}|R}}</nowiki></code> <br/> → {{formatnum:{{formatnum:987654321.654321}}|R}} (on any locale)
** <code><nowiki>{{formatnum:00001}}</nowiki></code> <br/> → {{formatnum:00001}}
** <code><nowiki>{{formatnum:987654321.654321 |NOSEP}}</nowiki></code> <br/> → {{formatnum:987654321.654321 |NOSEP}}
** Examples with [[wikipedia:Bengali numerals|{{#language:bn|en}} locale]]:
*** <code><nowiki>{{formatnum:987654321.654321}}</nowiki></code> <br/> → ৯৮,৭৬,৫৪,৩২১.৬৫৪৩২১
*** <code><nowiki>{{formatnum:987654321.654321 |NOSEP}}</nowiki></code> <br/> → ৯৮৭৬৫৪৩২১.৬৫৪৩২১
*** <code><nowiki>{{formatnum:৯৮,৭৬,৫৪,৩২১.৬৫৪৩২১ |R}}</nowiki></code> <br/> → 987654321.654321
----
Unsupported:<br />
<code><nowiki>{{formatnum:{{formatnum:987.654.321}}}}</nowiki></code> <br/> → 987 654 321 (e.g. with Italian locale)
----
Examples of wrong input (unreliable output), with or without <code>|R</code>: <br />
<code><nowiki>{{formatnum:987,654.321|R}}</nowiki></code> (the least broken) <br/>
<code><nowiki>{{formatnum:987.654,321|R}}</nowiki></code> <br/>
<code><nowiki>{{formatnum:987 654,321|R}}</nowiki></code> <br/>
<code><nowiki>{{formatnum:987&amp;nbsp;654,321|R}}</nowiki></code>
| {{Anchor|formatnum}}
Takes an unformatted number ([[wikipedia:Arabic numerals|Arabic]], no group separators and <code>.</code> as decimal separator) and outputs it in the localized digit script and formatted with decimal and decimal group separators, according to the wiki's default locale. <br />
The <code><nowiki>|R</nowiki></code> parameter can be used to reverse the behavior, for use in mathematical situations: it's reliable and should be used only to deformat numbers which are known to be formatted exactly as formatnum formats them with the wiki's locale.<br/>
The <code>NOSEP</code> ("no separators") parameter means that no group / decimal separators are changed; formatnum will only transform the digits themselves in languages which don't use the [[wikipedia:en:Hindu–Arabic numeral system|Hindu–Arabic numeral system]]. <code>NOSEP</code> can also prevent non-standard digit groupings you wouldn't expect.

{{warning|Leading zeroes are not removed, you can use <nowiki>{{#expr:00001}}</nowiki> instead (from [[mw:Extension:ParserFunctions|Extension:ParserFunctions]]).}}<br />

{{warning|If you don't input numbers in the exact format required, don't expect any reliable output, especially on non-English wikis.}}<br />
----

If you really need to format (according the wiki's locale) a number in unknown input format, you could try and use <code>formatnum</code> two times (but not if it can have a decimal group, or its separator will be eaten or the number won't be formatted). Be aware that this is more a hack than a regular way to proceed, thus the output may be not reliable.
|-
|
<code><nowiki>{{#dateformat:</nowiki>''date''<nowiki>}}</nowiki></code><br />
<code><nowiki>{{#formatdate:</nowiki>''date''<nowiki>}}</nowiki></code><br />
<code><nowiki>{{#dateformat:</nowiki>''date''{{!}}''format''<nowiki>}}</nowiki></code><br />
<code><nowiki>{{#formatdate:</nowiki>''date''{{!}}''format''<nowiki>}}</nowiki></code>
| 
<code><nowiki>{{#dateformat:25 dec 2009|ymd}}</nowiki></code> <br/>
→ {{#dateformat:25 dec 2009|ymd}} (your pref), 2009 Dec 25 (default) <br/>
<code><nowiki>{{#formatdate:dec 25,2009|dmy}}</nowiki></code> <br/>
→ {{#formatdate:dec 25,2009|dmy}} (your pref), 25 Dec 2009 (default) <br/>
<code><nowiki>{{#dateformat:2009-12-25|mdy}}</nowiki></code> <br/>
→ {{#dateformat:2009-12-25|mdy}} (your pref), December 25, 2009 (default) <br/>
<code><nowiki>{{#formatdate:2009 dec 25|ISO 8601}}</nowiki></code> <br/>
→ {{#formatdate:2009 dec 25|ISO 8601}} (your pref), 2009-12-25 (default) <br/>
<code><nowiki>{{#dateformat:25 decEmber|mdy}}</nowiki></code> <br/>
→ {{#dateformat:25 decEmber|mdy}} (your pref), DecEmber 25 (default) <br/>
''Note:'' In the example hereinbefore, "your pref" refers to your date preference on the current MediaWiki wiki only.
| {{Anchor|dateformat|formatdate}}Formats an unlinked date based on user "date format" preference, and adds metadata tagging it as a formatted date. For logged-out users and those who have not set a date format in their preferences, dates can be given a default: <code>mdy</code>, <code>dmy</code>, <code>ymd</code>, <code>ISO&nbsp;8601</code> (all case sensitive). If only the month and day are given, only <code>mdy</code> and <code>dmy</code> are valid. If a format is not specified or is invalid, the input format is used as a default. If the supplied date is not recognized as a valid date (specifically, if it contains any metadata such as from a nested use of these or similar templates), it is rendered unchanged, and no (additional) metadata is generated. <br/>

{{warning|Although the ISO 8601 standard requires that dates be in the Gregorian calendar, the ISO parameter in this function will still format dates that fall outside the usual Gregorian range (e.g. dates prior to 1583). Also, the magic word cannot properly convert between negative years (used with ISO 8601) and years BC or years BCE (used in general writing).}}
|-
| <code><nowiki>{{lc:</nowiki>''string''<nowiki>}}</nowiki></code>
| <code><nowiki>{{lc:DATA CENTER}}</nowiki></code> → {{lc:DATA CENTER}}
| {{Anchor|lc|Lc|LC}}The lowercase input.
|-
| <code><nowiki>{{lcfirst:</nowiki>''string''<nowiki>}}</nowiki></code>
| <code><nowiki>{{lcfirst:DATA center}}</nowiki></code> → {{lcfirst:DATA center}}
| {{Anchor|lcfirst|Lcfirst|LCFIRST}}The input with the <u>very first</u> character lowercase.
|-
| <code><nowiki>{{uc:</nowiki>''string''<nowiki>}}</nowiki></code>
| <code><nowiki>{{uc:text transform}}</nowiki></code> → {{uc:text transform}}
| {{Anchor|uc|Uc|UC}}The uppercase input.
|-
| <code><nowiki>{{ucfirst:</nowiki>''string''<nowiki>}}</nowiki></code>
| <code><nowiki>{{ucfirst:text tRAnSFORM}}</nowiki></code> → {{ucfirst:text tRAnSFORM}}
| {{Anchor|ucfirst|Ucfirst|UCFIRST}}The input with the <u>very first</u> character uppercase.
|-
| <code><nowiki>{{padleft:xyz|</nowiki>''stringlength''<nowiki>}}</nowiki></code> <br />
<code><nowiki>{{padleft:xyz|</nowiki>''strlen''<nowiki>|</nowiki>''char''<nowiki>}}</nowiki></code> <br />
<code><nowiki>{{padleft:xyz|</nowiki>''strlen''<nowiki>|</nowiki>''string''<nowiki>}}</nowiki></code>
| <code><nowiki>{{padleft:xyz|5}}</nowiki></code> → {{padleft:xyz|5}} <br /> 
<code><nowiki>{{padleft:xyz|5|_}}</nowiki></code> → {{padleft:xyz|5|_}} <br />
<code><nowiki>{{padleft:xyz|5|abc}}</nowiki></code> → {{padleft:xyz|5|abc}}<br />
<code><nowiki>{{padleft:xyz|2}}</nowiki></code> → {{padleft:xyz|2}} <br /> 
<code><nowiki>{{padleft:|1|xyz}}</nowiki></code> → {{padleft:|1|xyz}} 
(first character of the string) <br />
| {{Anchor|padleft}}
Inserts a string of padding characters (character chosen in third parameter; default "0") of a specified length (second parameter) next to a chosen base character or variable (first parameter). The final digits or characters in the base replace the final characters in the padding; i.e. <code><nowiki>{{padleft:44|3|0}}</nowiki></code> produces {{padleft:44|3}}. The padding string may be truncated if its length does not evenly divide the required number of characters.

All characters of the third parameter are used.
|-
| <code><nowiki>{{padright:xyz|</nowiki>''stringlength''<nowiki>}}</nowiki></code> <br /><code><nowiki>{{padright:xyz|</nowiki>''strlen''<nowiki>|</nowiki>''char''<nowiki>}}</nowiki></code> <br /><code><nowiki>{{padright:xyz|</nowiki>''strlen''<nowiki>|</nowiki>''string''<nowiki>}}</nowiki></code>
| <code><nowiki>{{padright:xyz|5}}</nowiki></code> → {{padright:xyz|5}} <br />
<code><nowiki>{{padright:xyz|5|_}}</nowiki></code> → {{padright:xyz|5|_}} <br />
<code><nowiki>{{padright:xyz|5|abc}}</nowiki></code> → {{padright:xyz|5|abc}} <br />
<code><nowiki>{{padright:xyz|2}}</nowiki></code> → {{padright:xyz|2}} <br />
<code><nowiki>{{padright:|1|xyz}}</nowiki></code> → {{padright:|1|xyz}} <br />
| {{Anchor|padright}}Identical to <code>padleft</code> but adds padding characters to the right side.
|}
'''See also:''' [[mw:Extension:StringFunctions|Extension:StringFunctions]] (not installed).

===Localization===
Here are the magic words which are used as main localisation tools. Other magic words will often depend on the wiki's locale and configuration or on the chosen language: see in particular [[#Date and time|#Date and time]], [[#Formatting|#Formatting]], [[#Miscellaneous|#Miscellaneous]]. More magic words can be added by the [[mw:Extension:Translate|Extension:Translate]].

{| class="wikitable"
! width="10%" | Usage
! width="40%" | Input → Output
! Description
|-
| {{Anchor|plural|Plural|PLURAL}}<code><nowiki>{{plural:2|</nowiki>''is''<nowiki>|</nowiki>''are''<nowiki>}}</nowiki></code>
| <code><nowiki>{{plural:0|is|are}}</nowiki></code> → {{plural:0|is|are}}<br /><code><nowiki>{{plural:1*1|is|are}}</nowiki></code> → {{plural:1*1|is|are}}<br /><code><nowiki>{{plural:21 mod 10|is|are}}</nowiki></code> → {{plural:21 mod 10|is|are}}<br /><code><nowiki>{{plural:{{#expr:21 mod 10}}|is|are}}</nowiki></code> → {{plural:{{#expr:21 mod 10}}|is|are}}<br /><code><nowiki>{{plural:1|is|are}}</nowiki></code> → {{plural:1|is|are}}<br /><code><nowiki>{{plural:2|is|are}}</nowiki></code> → {{plural:2|is|are}}<br /><code><nowiki>{{plural:-1|is|are}}</nowiki></code> → {{plural:-1|is|are}}<br /><code><nowiki>{{plural:-2|is|are}}</nowiki></code> → {{plural:-2|is|are}}<br /><code><nowiki>{{plural:0.5|is|are}}</nowiki></code> → {{plural:0.5|is|are}}<br /><code><nowiki>{{plural:1.5|is|are}}</nowiki></code> → {{plural:1.5|is|are}}<br /><code><nowiki>{{plural:-0.5|is|are}}</nowiki></code> → {{plural:-0.5|is|are}}<br /><code><nowiki>{{plural:-1.5|is|are}}</nowiki></code> → {{plural:-1.5|is|are}}<br /> (For [[wikipedia:Russian language|Russian]])<br /><code><nowiki>{{PLURAL:5|1=Категория|Категории}} </nowiki></code>&nbsp;→&nbsp;Категории
<br /><code><nowiki>{{PLURAL:3|страница|страницы|страниц}}</nowiki></code>&nbsp;→&nbsp;страницы<br /><code><nowiki>{{PLURAL:5|страница|страницы|страниц}}</nowiki></code>&nbsp;→&nbsp;страниц
| Outputs the singular form (second parameter) if the absolute value of the first parameter is an expression equalling one; the plural form (third parameter) otherwise. Its functioning is [[#Language-dependent_word_conversions|language-dependent]].
|-
| {{Anchor|grammar|Grammar|GRAMMAR}}<code><nowiki>{{grammar:N|</nowiki>''noun''<nowiki>}}</nowiki></code>
| 
| Outputs the correct inflected form of the given word described by the inflection code after the colon ([[#Language-dependent_word_conversions|language-dependent]]). Grammar transformations are used for inflected languages like Polish. See also [[mw:Manual:$wgGrammarForms|$wgGrammarForms]].
|-
| {{Anchor|gender|Gender|GENDER}}<code><nowiki>{{gender:username|text for every gender}}</nowiki></code><br />
<code><nowiki>{{gender:Username|male text|female text|text for unspecified}}</nowiki></code><br />
<code><nowiki>{{gender:|male text|female text|text for unspecified}}</nowiki></code><br />
<code><nowiki>{{gender:.|male text|female text|text for unspecified}}</nowiki></code><br />
| ''(Depends on the named user's gender)''
| A switch for the gender set in [[Special:Preferences]]. <br/>
''Note:'' The first example is basically a no-op<br/>
''Note:'' If 3rd parameter is omitted and user hasn't defined their gender, then <code>''text if user is male''</code> is returned.<br>A blank username field (<nowiki>{{gender:|</nowiki>) means the current user, but can be used only in interface messages (MediaWiki namespace).<br>
A dot username (.) means the default user gender on this wiki.
|-
| {{Anchor|int|INT}}<code><nowiki>{{int:</nowiki>''message name''<nowiki>}}</nowiki></code>
| <code><nowiki>{{int:</nowiki>edit<nowiki>}}</nowiki></code> &rarr; '''{{int:edit}}''' <br /><small>''(Depends on user language; try: [{{fullurl:{{FULLPAGENAME}}|uselang=fr}}#Localisation fr] &bull; [{{fullurl:{{FULLPAGENAME}}|uselang=ja}}#Localisation ja])''</small>
| Internationalizes (translates) the given '''int'''erface (MediaWiki namespace) message into the user language. For <code>msgnw</code> and other transclusion magic words, see the [[#Transclusion modifiers|Transclusion modifiers]] section.
|-
| <code><nowiki>{{int:editsectionhint|MediaWiki}}</nowiki></code>
| <code><nowiki>{{int:editsectionhint|MediaWiki}}</nowiki></code> &rarr; '''{{int:editsectionhint|MediaWiki}}'''
| You may also use parameters with translations. <br />Parameters are designated in messages with: $1, $2, $3, etc. <br />For example, here is the message for ''editsectionhint'': Edit section: $1 <br />In this example, MediaWiki replaces $1.
|}

===Transclusion modifiers===
<code><nowiki>{{</nowiki>''Page name''|''optional params''}}</code> usually transcludes another page, by default from the Template:namespace. These magic words modify that behavior.
{| class="wikitable plainlinks"
! width="15%" | Usage
! width="15%" | Output
! Description
|-
| <code><nowiki>{{:xyz}}</nowiki></code>
|
| A bare colon is not a template modifier but the prefix for the main namespace. Since transclusion defaults to the Template namespace, you would use for example, {&#123;:UTC&#125;} (vs. {&#123;UTC&#125;}) to include the text of the main namespace article UTC rather than Template:UTC.
|-
| <code><nowiki>{{int:xyz}}</nowiki></code>
|
| Same as <nowiki>{{MediaWiki:xyz}}</nowiki>, except standard message translation is applied depending on subpages and content/user/uselang language. Another difference is: this doesn't appear under "Templates used in this preview". Rendered as {{int:xyz}} if [[MediaWiki:xyz]] doesn't exist. See also [[mw:Help:System message|Help:System message]].
|-
| <code><nowiki>{{msg:xyz}}</nowiki></code><br /><code><nowiki>{{raw:xyz}}</nowiki></code>
|
| Even if there is a magic word named "xyz", use template:xyz unless the template doesn't exist (equivalent to <nowiki>{{template:xyz}}</nowiki>). Normally, magic words have priority when there is a conflict.
|-
|<code><nowiki>{{raw:xyz}}</nowiki></code>
|
| If [[mw:Manual:$wgEnableScaryTranscluding|$wgEnableScaryTranscluding]] is enabled, and this is an interwiki transclusion, include the raw wikitext instead of the html from the foreign wiki.
|-
| <code><nowiki>{{msgnw:xyz}}</nowiki></code>
|
| The unexpanded wikitext is rendered (more or less, for details see [[Help:Template#Usage]]).
|-
| <code><nowiki>{{subst:xyz}}</nowiki></code>
|
| In the wikitext, the tag is substituted by the ''content'' (single-level evaluation only), see [[Help:Template#Usage]].
|-
| <code><nowiki>{{safesubst:xyz}}</nowiki></code>
|
| See [[Help:Template#Usage]].
|}

===Miscellaneous===
{| class="wikitable plainlinks"
! width="15%" | Usage
! width="15%" | Output
! Description
|-
| <code><nowiki>{{#language:</nowiki>''language code''<nowiki>}}</nowiki></code><br /><code><nowiki>{{#language:ar}}</nowiki></code> <br /><code><nowiki>{{#language:</nowiki>''language code''<nowiki>|</nowiki><br />''target language code''<nowiki>}}</nowiki></code> <br /><code><nowiki>{{#language:ar|en}}</nowiki></code>
| {{#language:language code}} <br />{{#language:ar}} <br />{{#language:language code|target language code}} <br />Arabic
| The full name of the language for the given [[mw:Manual:Language#lang-code|language code]]: native name (language autonym) by default, name translated in target language if a target language code is specified.[[mw:Extension:CLDR|Extension:CLDR]] (not currently installed) must be installed for the translation to work.
|-
| <code><nowiki>{{#special:</nowiki>''special page name''<nowiki>}}</nowiki> <br /><nowiki>{{#special:userlogin}}</nowiki></code>
| {{#special:special page name}} <br />{{#special:userlogin}}
| The localized name for the given canonical Special: page.
|-
| <code><nowiki>{{#speciale:</nowiki>''special page name''<nowiki>}}</nowiki> <br /><nowiki>{{#speciale:userlogin}}</nowiki></code>
| {{#speciale:special page name}} <br />{{#speciale:userlogin}}
| The localized and URL-encoded name for the given canonical Special: page.
|-
| <code><nowiki>{{#tag:</nowiki>''tagname'' <br/><nowiki>|</nowiki>''content'' <br/><nowiki>|</nowiki>''attribute1=value1'' <br /><nowiki>|</nowiki>''attribute2=value2''<br /><nowiki>}}</nowiki></code>
| ''(Depends on parser tag)''
| Alias for XML-style MediaWiki parser tags or extension tags. It allows a [[mw:Manual:Tag extensions#How do I render wikitext in my extension?|pre-save transform of wiki code]] and [[mw:Extension:ParserFunctions|Extension:ParserFunctions]] within tags before the tag is processed. It also prevents parsing of tags in conditional paths that aren't executed (like in <code>#if</code> statements). Content between tags is passed as the first parameter, and any attributes for the tags can be passed as subsequent parameters. This example:

<code>&lt;tagname ''attribute1''="''value1''"<br />''attribute2''="''value2''"&gt;</code>''Your content goes here''<code>&lt;/tagname&gt;</code>

…can be rewritten like this:

<code><nowiki>{{#tag:</nowiki></code>''tagname''<code><nowiki>|</nowiki></code>''Your content goes here''<code><nowiki>|</nowiki></code>''attribute1''=''value1''<code><nowiki>|</nowiki></code>''attribute2''=''value2''<code><nowiki>}}</nowiki></code>

Example for the [[mw:Extension:Cite|Cite extension]]'s (installed here) <code>&lt;ref&gt;</code> tags:

<code><nowiki>{{#tag:ref|Citation text goes here, and you can include parser functions like {{#expr: ... }} and magic words like {{PAGENAME}}.|name="multiple"}}</nowiki></code>

{{warning|You must write <code><nowiki>{{#tag:</nowiki></code>''tagname''<code><nowiki>||</nowiki></code>''attribute1''<nowiki>=</nowiki>''value1''<code><nowiki>|</nowiki></code>''attribute2''<nowiki>=</nowiki>''value2''<code><nowiki>}}</nowiki></code> to pass an empty content. No leading or trailing space of the text content are permitted between the pipe characters <code><nowiki>||</nowiki></code> before ''attribute1''.}}
|}

==ParserFunctions Extension==
The [[mw:Extenssion:ParserFunctions|Extenssion:ParserFunctions]] extension provides eleven additional parser functions to supplement the "magic words", which are already present in MediaWiki. All the parser functions provided by this extension take the form:
<code><nowiki>{{</nowiki>'''#functionname''': ''argument 1'' | ''argument 2'' | ''argument 3'' ... <nowiki>}}</nowiki></code>

===#expr===
{| class="wikitable" style="float:right; width:30%; margin-left:1em;"
|-
! style="font-size: larger" | Type
! style="font-size: larger" | Operators
|-
! Grouping (parentheses)
| style="word-spacing: 0.5em; font-weight: bold;" | <code>( )</code>
|-
! Numbers
| <code>'''1234.5'''</code> &nbsp; <code>'''e'''</code>&nbsp;(2.718) &nbsp; <code>'''pi'''</code>&nbsp;(3.142)
|-
!
| binary operator <code>'''e'''</code> &nbsp; unary <code>'''+'''</code>,<code>'''-'''</code>
|-
! Unary
| style="word-spacing: 0.5em; font-weight: bold;" | <code>not ceil trunc floor abs exp ln sin cos tan acos asin atan</code>
|-
! rowspan="3" | Binary
| style="word-spacing: 0.5em; font-weight: bold;" | <code>^</code>
|-
| style="word-spacing: 0.5em; font-weight: bold;" | <code>* / div mod</code>
|-
| style="word-spacing: 0.5em; font-weight: bold;" | <code>+ -</code>
|-
! Round
| style="word-spacing: 0.5em; font-weight: bold;" | <code>round</code>
|-
! rowspan="3" | Logic
| style="word-spacing: 0.5em; font-weight: bold;" | <code>= != <> > < >= <=</code>
|-
| style="word-spacing: 0.5em; font-weight: bold;" | <code>and</code>
|-
| style="word-spacing: 0.5em; font-weight: bold;" | <code>or</code>
|}

This function evaluates a mathematical expression and returns the calculated value. This function is also available in [[mw:Extension:Scribunto|Extension:Scribunto]] via the <code>mw.ext.ParserFunctions.expr</code> function.

:<code><nowiki>{{#expr:</nowiki> ''expression'' <nowiki>}}</nowiki></code>

The available operators are listed to the right, in order of precedence. See [[mw:Help:Calculation|Help:Calculation]] for more details of the function of each operator. The accuracy and format of the result returned will vary depending on the operating system of the server running the wiki and the number format of the site language.

When evaluating using [[wikipedia:boolean algebra|boolean algebra]], zero evaluates to <code>false</code>, and any nonzero value, positive or negative, evaluates to <code>true</code>
:<code><nowiki>{{#expr: 1 and -1 }}</nowiki></code> → '''{{#expr: 1 and -1 }}'''
:<code><nowiki>{{#expr: 1 and 0 }}</nowiki></code> → '''{{#expr: 1 and 0 }}'''
:<code><nowiki>{{#expr: 1 or -1 }}</nowiki></code> → '''{{#expr: 1 or -1 }}'''
:<code><nowiki>{{#expr: -1 or 0 }}</nowiki></code> → '''{{#expr: -1 or 0 }}'''
:<code><nowiki>{{#expr: 0 or 0 }}</nowiki></code> → '''{{#expr: 0 or 0 }}'''

An empty input expression returns an empty string. Invalid expressions return one of several error messages, which can be caught using the <code>[[#iferror|#iferror]]</code> function:
:<code><nowiki>{{#expr: }}</nowiki></code> → ''' {{#expr: }}'''
:<code><nowiki>{{#expr: 1+ }}</nowiki></code> → '''{{#expr: 1+ }}'''
:<code><nowiki>{{#expr: 1 = }}</nowiki></code> → '''{{#expr: 1 = }}'''
:<code><nowiki>{{#expr: 1 foo 2 }}</nowiki></code> → '''{{#expr: 1 foo 2 }}'''

The order of addition and subtraction operands before or after a number is meaningful and may be treated as a positive or negative value instead of as an operand with an erroneous input:
:<code><nowiki>{{#expr: +1 }}</nowiki></code> → '''{{#expr: +1 }}'''
:<code><nowiki>{{#expr: -1 }}</nowiki></code> → '''{{#expr: -1 }}'''
:<code><nowiki>{{#expr: + 1 }}</nowiki></code> → '''{{#expr: + 1 }}'''
:<code><nowiki>{{#expr: - 1 }}</nowiki></code> → '''{{#expr: - 1 }}'''

Note, if using the output of magic words, you must raw-format them in order to remove commas and translate the numerals. For example, <nowiki>{{NUMBEROFUSERS}}</nowiki> results in {{NUMBEROFUSERS}}, where we want {{formatnum:{{NUMBEROFUSERS}}|R}}, which can be obtained using <code><nowiki>{{</nowiki>[[#Formatting|formatnum]]<nowiki>:{{NUMBEROFUSERS}}|R}}</nowiki></code>. This is especially important in some languages, where numerals are translated. For example, in Bengali, <nowiki>{{NUMBEROFUSERS}}</nowiki> produces ৩০,০৬১.
:<code><nowiki>{{#expr:{{NUMBEROFUSERS}}+100}}</nowiki></code> → ''' {{#expr:{{NUMBEROFUSERS}}+100}}'''
:<code><nowiki>{{#expr:{{formatnum:{{NUMBEROFUSERS}}|R}}+100}}</nowiki></code> → '''{{#expr:{{formatnum:{{NUMBEROFUSERS}}|R}}+100}}'''


{{Warning|The operator <code>mod</code> gives wrong results for some values of the second argument:
<!-- the following line now produces the correct value:
:<code><nowiki>{{#expr: 123 mod (2^32-1)}}</nowiki></code> → '''{{#expr: 123 mod (2^32-1)}}''' (should be 123)<br />
but see this one: -->
:<code><nowiki>{{#expr: 123 mod (2^64-1)}}</nowiki></code> → {{#expr: 123 mod (2^64-1)}} (produces an empty string; should be 123)<br />
<!-- and the following bug has now been solved, as shown on the linked bug report:
Depending on the specification and configuration of the server running the wiki, there may also be other errors:
:<code><nowiki>{{#expr: 20060618093259 mod 10000}}</nowiki></code> → '''{{#expr: 20060618093259 mod 10000}}''' in most cases, but may occasionally give '''-6357'''. See {{bugzilla|6356}}.
-->
}}
'''Note: If you want to do calculations based on dates (ex. test whether current date and time is after some other date and time), first convert the time to number of seconds after January 1, 1970 using <nowiki>{{#time: xNU }}</nowiki>, then you can simply add and subtract dates as numbers.'''

====Rounding====
[https://php.net/function.round Rounds] off the number on the left to a multiple of 1/10 raised to a power, with the exponent equal to the truncated value of the number given on the right.
To round up or down use unary <code>ceil</code> or <code>floor</code> respectively.

{| class="wikitable"
! Test case
! Result
! Method of rounding
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> 1/3 round 5 }}</code> || {{#expr: 1/3 round 5 }} || Final digit is < 5, so no apparent rounding occurs
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr: 1/6 round 5 }}</nowiki></code> || {{#expr: 1/6 round 5 }} || Final digit is ≥ 5, so it is rounded up
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr: 8.99999/9 round 5 }}</nowiki></code> || {{#expr: 8.99999/9 round 5 }} || Again, the result is rounded up on the last digit, which results in additional rounding
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> 1234.5678 '''round -2''' }}</code> || {{#expr: 1234.567 round -2 }} || Rounded to nearest 100 because negative values round to the left of the decimal point
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> 1234.5678 '''round 2''' }}</code> || {{#expr: 1234.567 round 2 }} || Rounded to nearest 100th because positive values round to the right of the decimal point
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> 1234.5678 round 2'''.3''' }}</code> || {{#expr: 1234.567 round 2.3 }} || Decimals in the rounding index make no difference in the rounded result
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> '''trunc''' 1234.5678 }}</code> || {{#expr: trunc 1234.567 }} || <translate><!--T:34--> Decimal portion truncated (chopped off)</translate>
|-
! colspan=3 | Rounding to the nearest integer
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> 1/3 '''round 0''' }}</code> || {{#expr: 1/3 round 0 }} || Down to the ''nearest'' integer, which is zero
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> 1/2 '''round 0''' }}</code> || {{#expr: 1/2 round 0 }} || Up to the nearest integer, which is one
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> 3/4 '''round 0''' }}</code> || {{#expr: 3/4 round 0 }} || Up to the nearest integer, which is one
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> -1/3 '''round 0''' }}</code> || {{#expr: -1/3 round 0 }} || Up to the nearest integer, which is zero
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> -1/2 '''round 0''' }}</code> || {{#expr: -1/2 round 0 }} || Down to the nearest integer, which is negative one
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> -3/4 '''round 0''' }}</code> || {{#expr: -3/4 round 0 }} || Down to the nearest integer, which is negative one
|-
! colspan=3 {{hl2}} | Rounding up or down with ''ceil'' and ''floor''
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> '''ceil('''1/3''')''' }}</code> || {{#expr: ceil(1/3) }} || Up to the next ''larger'' integer, which is one
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> '''floor('''1/3''')''' }}</code> || {{#expr: floor(1/3) }} || Down to the next ''smaller'' integer, which is zero
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> '''ceil('''-1/3''')''' }}</code> || {{#expr: ceil(-1/3) }} || Up to the next larger integer, which is zero
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> '''floor('''-1/3''')''' }}</code> || {{#expr: floor(-1/3) }} || Down to the next smaller integer, which is negative one
|-
| <code style="white-space:nowrap;"><nowiki>{{#expr:</nowiki> '''ceil''' 1/3 }}</code> || {{#expr: ceil 1/3 }} || Not rounded, since 1 already is an integer<br />{{Warning|Interpreted as '''(ceil''' 1''')'''/3, not '''ceil('''1/3''')''', as you might expect}}
|}

====Strings====
Expressions only work with number-like values, they cannot compare strings or characters. [[#ifeq]] can be used instead.
:<code><nowiki>{{#expr: "a" = "a" }}</nowiki></code> → '''{{#expr: "a" = "a" }}'''
:<code><nowiki>{{#expr: a = a }}</nowiki></code> → '''{{#expr: a = a }}'''
:<code><nowiki>{{#ifeq: a | a | 1 | 0 }}</nowiki></code> → '''{{#ifeq: a | a | 1 | 0 }}'''

===#if===
This function evaluates a test string and determines whether or not it is empty. A test string containing only white space is considered to be empty.
:<code><nowiki>{{#if:</nowiki> ''test string'' | ''value if test string is not empty'' | ''value if test string is empty (or only white space)'' <nowiki>}}</nowiki></code>
:<code><nowiki>{{#if:</nowiki>first parameter | second parameter | third parameter <nowiki>}}</nowiki></code>

This function first tests whether the first parameter is not empty. If the first parameter is not empty the function displays the second argument. If the first parameter is empty or contains only whitespace characters (spaces, newlines, etc.) it displays the third argument.
:<code><nowiki>{{#if: | yes | no}}</nowiki></code> → '''{{#if: | yes | no}}'''
:<code><nowiki>{{#if: string | yes | no}}</nowiki></code> → '''{{#if: string | yes | no}}'''
:<code><nowiki>{{#if: &nbsp;&nbsp;&nbsp;&nbsp; | yes | no}}</nowiki></code> → '''{{#if:        | yes | no}}'''
:<code><nowiki>{{#if: </nowiki><br /><br /><br /><nowiki> | yes | no}}</nowiki></code> → '''{{#if: 

| yes | no}}'''

The test string is always interpreted as pure text, so mathematical expressions are not evaluated:
:<code><nowiki>{{#if: 1==2 | yes | no }}</nowiki></code> → '''{{#if: 1==2 | yes | no}}'''
:<code><nowiki>{{#if: 0 | yes | no }}</nowiki></code> → '''{{#if: 0 | yes | no }}'''

The last parameter (false) may be omitted:
:<code><nowiki>{{#if: foo | yes }}</nowiki></code> → ''' {{#if: foo | yes }}'''
:<code><nowiki>{{#if: | yes }}</nowiki></code> → ''' {{#if: | yes }}'''
:<code><nowiki>{{#if: foo | | no}}</nowiki></code> → ''' {{#if: foo | | no}}'''

The function may be nested. To do so, nest the inner #if function in its full form in place of a parameter of the enclosing #if function. Up to seven levels of nesting is possible, although that may depend on the wiki or a memory limit.
:<code><nowiki>{{#if: test string | value if test string is not empty | {{#if: test string | value if test string is not empty | value if test string is empty (or only white space) >}} }}</nowiki></code>

You can also use a parameter as the test string in your #if statement.  You need to ensure you add the <code>|</code> (pipe symbol) after the name of the variable.
(So that if the parameter does not have a value, it evaluates to an empty string instead of the string "<code><nowiki>{{{1}}}</nowiki></code>".)

:<code><nowiki>{{#if:{{{1</nowiki><span style="color:red; font-weight:bold">|</span>}}}|You entered text in variable 1|There is no text in variable 1 }}</code>

See [[mw:Help:Parser functions in templates|Help:Parser functions in templates]] for more examples of this parser function.

===#ifeq===
{{Anchor|ifeq|IFEQ|Ifeq|IfEq|If equal}}
This parser function compares two input strings, determines whether they are identical, and returns one of two strings based on the result. If more comparisons and output strings are required, consider using <code>#switch</code>.
:<code><nowiki>{{#ifeq:</nowiki> ''string 1'' <nowiki>|</nowiki> ''string 2'' <nowiki>|</nowiki> ''value if identical'' <nowiki>|</nowiki> ''value if different'' <nowiki>}}</nowiki></code>

If both strings are valid numerical values, the strings are compared numerically:
:<code><nowiki>{{#ifeq: 01 | 1 | equal | not equal}}</nowiki></code> → '''{{#ifeq: 01 | 1 | equal | not equal}}'''
:<code><nowiki>{{#ifeq: 0 | -0 | equal | not equal}}</nowiki></code> → '''{{#ifeq: 0 | -0 | equal | not equal}}'''
:<code><nowiki>{{#ifeq: 1e3 | 1000 | equal | not equal}}</nowiki></code> → '''{{#ifeq: 1e3 | 1000 | equal | not equal}}'''
:<code><nowiki>{{#ifeq: {{#expr:10^3}} | 1000 | equal | not equal}}</nowiki></code> → '''{{#ifeq: {{#expr:10^3}} | 1000 | equal | not equal}}'''

Otherwise the comparison is made as text; this comparison is case sensitive:
:<code><nowiki>{{#ifeq: foo | bar | equal | not equal}}</nowiki></code> → '''{{#ifeq: foo | bar | equal | not equal}}'''
:<code><nowiki>{{#ifeq: foo | Foo | equal | not equal}}</nowiki></code> → '''{{#ifeq: foo | Foo | equal | not equal}}'''
:<code><nowiki>{{#ifeq: "01" | "1" | equal | not equal}}</nowiki></code> → '''{{#ifeq: "01" | "1" | equal | not equal}}''' &nbsp;''
(compare to similar example above, without the quotes)''
:<code><nowiki>{{#ifeq: 10^3 | 1000 | equal | not equal}}</nowiki></code> → '''{{#ifeq: 10^3 | 1000 | equal | not equal}}''' &nbsp;''(compare to similar example above, with <code>[[##expr|#expr]]</code> returning a valid number first)''

As a practical example, consider an existing [[Help:Templates|template]] <code>Template:Timer</code> using the parser to choose between two standard times, short and long. It takes the parameter as the first input to compare against the string "short" &ndash; there is no convention for the order, but it is simpler to read if the parameter goes first. The template code is defined as:
:<code><nowiki>{{#ifeq: {{{1|}}} | short | 20 | 40 }}</nowiki></code>

the following ensue:
:<code><nowiki>{{timer|short}}</nowiki></code> → '''20'''
:<code><nowiki>{{timer|20}}</nowiki></code> → '''40'''
:<code><nowiki>{{timer}}</nowiki></code> → '''40'''

{{Warning|<code>[[##ifexpr|#ifexpr]]</code> does not report equivalent numerical comparisons with the <code>#ifeq</code> and <code>[[##switch|#switch]]</code> parsers. These latter two are more accurate than <code>[[##ifexpr|#ifexpr]]</code>, and do not return equivalent results.
Consider these comparison with the final digit changed:
:<code><nowiki>{{#ifeq: 12345678901234567 | 12345678901234568 | equal | not equal}}</nowiki></code> → '''{{#ifeq: 12345678901234567 | 12345678901234568 | equal | not equal}}'''
:<code><nowiki>{{#switch: 12345678901234567 | 12345678901234568 = equal | not equal}}</nowiki></code> → '''{{#switch: 12345678901234567 | 12345678901234568 = equal | not equal}}'''
Because PHP used in <code>#ifeq</code> and <code>[[##switch|#switch]]</code> compares two numbers of type integer, it returns the expected result correctly.

Whereas with <code>[[##ifexpr|#ifexpr]]</code> and the same numbers:
:<code><nowiki>{{#ifexpr: 12345678901234567 = 12345678901234568 | equal | not equal}}</nowiki></code> → '''{{#ifexpr: 12345678901234567 = 12345678901234568 | equal | not equal}}'''

With the different digit, the result of equal is actually incorrect.

This behaviour in <code>[[##ifexpr|#ifexpr]]</code> is caused because MediaWiki converts literal numbers in expressions to type float, which, for large integers like these, involves rounding.<br /><br />
}}

{{Warning|When used inside a parser function, any parser tags and other parser functions must be temporarily replaced with {{<tvar|1>ll|Strip marker</>|a unique code}}. This affects comparisons:
:<code><nowiki>{{#ifeq: &lt;nowiki>foo&lt;/nowiki> | &lt;nowiki>foo&lt;/nowiki> | equal | not equal}}</nowiki></code> → '''{{#ifeq: <nowiki>foo</nowiki> | <nowiki>foo</nowiki> | equal | not equal}} '''
:<code><nowiki>{{#ifeq: &lt;math>foo&lt;/math> | &lt;math>foo&lt;/math> | equal | not equal}}</nowiki></code> → '''{{#ifeq: <math>foo</math> | <math>foo</math> | equal | not equal}} '''
:<code><nowiki>{{#ifeq: {{</nowiki>[[Help:Magic words#Miscellaneous|#tag:]]<nowiki>math|foo}} | {{#tag:math|foo}} | equal | not equal}}</nowiki></code> → '''{{#ifeq: {{#tag:math|foo}} | {{#tag:math|foo}} | equal | not equal}} '''
:<code><nowiki>{{#ifeq: [[foo]] | [[foo]] | equal | not equal}}</nowiki></code> → '''{{#ifeq: [[foo]] | [[foo]] | equal | not equal}} '''

If the strings to be compared are given as equal calls to the same [[Help:Templates|template]] containing such tags, then the condition is true, but in the case of two templates with identical content containing such tags it is false.
}}

{{Warning|Literal comparisons to [[Help:Magic words#Page names|page-name magic words]] may fail depending on site configuration.
For example,  <nowiki>{{FULLPAGENAME}}</nowiki>, depending on wiki, may capitalize the first letter, and will replace all underscores with spaces.

To work around this, apply the magic word to both parameters:

:<code><nowiki>{{#ifeq: {{FULLPAGENAME: L'Aquila}} | {{FULLPAGENAME}} | equal | not equal}}</nowiki></code> → '''equal'''
}}

===#iferror===
This function takes an input string and returns one of two results; the function evaluates to <code>true</code> if the input string contains an HTML object with <code>class="error"</code>, as generated by other parser functions such as <code>[[##expr|#expr]]</code>, <code>[[##time|#time]]</code> and <code>[[##rel2abs|#rel2abs]]</code>, [[Help:Templates|template]] errors such as loops and recursions, and other "failsoft" parser errors.
:<code><nowiki>{{#iferror:</nowiki> ''test string'' <nowiki>|</nowiki> ''value if error'' <nowiki>|</nowiki> ''value if correct'' <nowiki>}}</nowiki></code>

One or both of the return strings can be omitted. If the <code>''correct''</code> string is omitted, the <code>''test string''</code> is returned if it is not erroneous. If the <code>''error''</code> string is also omitted, an empty string is returned on an error:
:<code><nowiki>{{#iferror: {{#expr: 1 + 2 }} | error | correct }}</nowiki></code> → '''{{#iferror: {{#expr: 1 + 2 }} | error | correct }}'''
:<code><nowiki>{{#iferror: {{#expr: 1 + X }} | error | correct }}</nowiki></code> → '''{{#iferror: {{#expr: 1 + X }} | error | correct }}'''
:<code><nowiki>{{#iferror: {{#expr: 1 + 2 }} | error }}</nowiki></code> → '''{{#iferror: {{#expr: 1 + 2 }} | error }}'''
:<code><nowiki>{{#iferror: {{#expr: 1 + X }} | error }}</nowiki></code> → '''{{#iferror: {{#expr: 1 + X }} | error }}'''
:<code><nowiki>{{#iferror: {{#expr: 1 + 2 }} }}</nowiki></code> → '''{{#iferror: {{#expr: 1 + 2 }} }}'''
:<code><nowiki>{{#iferror: {{#expr: 1 + X }} }}</nowiki></code> → '''&zwnj;{{#iferror: {{#expr: 1 + X }} }}'''<!-- maybe the zwnj protects the trailing space before no output -->
:<code><nowiki>{{#iferror: {{#expr: . }} | error | correct }}</nowiki></code> → '''{{#iferror: {{#expr: . }} | error | correct }}'''
:<code><nowiki>{{#iferror: <strong class="error">a</strong> | error | correct }}</nowiki></code> → '''{{#iferror: <strong class="error">a</strong> | error | correct }}'''

===#ifexpr===
This function evaluates a mathematical expression and returns one of two strings depending on the boolean value of the result:
:<code><nowiki>{{#ifexpr:</nowiki> ''expression'' <nowiki>|</nowiki> ''value if true'' <nowiki>|</nowiki> ''value if false'' <nowiki>}}</nowiki></code>

The <code>''expression''</code> input is evaluated exactly as for <code>[[##expr|#expr]]</code> above, with the same operators being available. The output is then evaluated as a boolean expression.
An empty input expression evaluates to <code>false</code>:
:<code><nowiki>{{#ifexpr: | yes | no}}</nowiki></code> → '''{{#ifexpr: | yes | no}}'''
As mentioned above, zero evaluates to <code>false</code> and any nonzero value evaluates to <code>true</code>, so this function is equivalent to one using <code>[[##ifeq|#ifeq]]</code> and <code>[[##expr|#expr]]</code> only:
:<code><nowiki>{{#ifeq: {{#expr: </nowiki>''expression''<nowiki> }} | 0 | </nowiki> ''value if false'' <nowiki>|</nowiki> ''value if true'' <nowiki>}}</nowiki></code>
except for an empty or wrong input expression (an error message is treated as an empty string; it is not equal to zero, so we get <code>''value if true''</code>).
:<code><nowiki>{{#ifexpr: = | yes | no }}</nowiki></code> → ''' {{#ifexpr: = | yes | no }}'''
comparing
:<code><nowiki>{{#ifeq: {{#expr: = }} | 0 | no | yes }}</nowiki></code> → ''' {{#ifeq: {{#expr: = }} | 0 | no | yes }}'''

Either or both the return values may be omitted; no output is given when the appropriate branch is left empty:
:<code><nowiki>{{#ifexpr: 1 > 0 | yes }}</nowiki></code> → '''{{#ifexpr: 1 > 0 | yes }}'''
:<code><nowiki>{{#ifexpr: 1 < 0 | yes }}</nowiki></code> → ''' {{#ifexpr: 1 < 0 | yes }}'''
:<code><nowiki>{{#ifexpr: 0 = 0 | yes }}</nowiki></code> → ''' {{#ifexpr: 0 = 0 | yes }}'''
:<code><nowiki>{{#ifexpr: 1 > 0 | | no}}</nowiki></code> → ''' {{#ifexpr: 1 > 0 | | no}}'''
:<code><nowiki>{{#ifexpr: 1 < 0 | | no}}</nowiki></code> → ''' {{#ifexpr: 1 < 0 | | no}}'''
:<code><nowiki>{{#ifexpr: 1 > 0 }}</nowiki></code> → ''' {{#ifexpr: 1 > 0 }}'''

===#ifexist===
{{Anchor|ifexist|Ifexist|ifExist|IfExist|IFexist|IFEXIST}}
This function takes an input string, interprets it as a page title, and returns one of two values depending on whether or not the page exists on the local wiki.
:<code><nowiki>{{#ifexist:</nowiki> ''page title'' | ''value if exists'' | ''value if doesn't exist'' <nowiki>}}</nowiki></code>

The function evaluates to <code>true</code> if the page exists, whether it contains content, is visibly blank (contains meta-data such as category links or [[Help:Magic words|magic words]], but no visible content), is blank, or is a [[Help:Redirects|redirect]]. Only pages that are redlinked evaluate to <code>false</code>, including if the page used to exist but has been deleted.
:<code><nowiki>{{#ifexist:</nowiki> {{FULLPAGENAME}} | exists | doesn't exist <nowiki>}}</nowiki></code> → '''{{#ifexist: {{FULLPAGENAME}} | exists | doesn't exist }}'''
:<code><nowiki>{{#ifexist:</nowiki> XX{{FULLPAGENAME}}XX | exists | doesn't exist <nowiki>}}</nowiki></code> → '''{{#ifexist: XX{{FULLPAGENAME}}XX | exists | doesn't exist }}'''

The function evaluates to <code>true</code> for [[mw:Help:System message|system messages]] that have been customized, and for [[Help:Special pages|special pages]] that are defined by the software.
:<code><nowiki>{{#ifexist:</nowiki> {{#special:Watchlist}} | exists | doesn't exist <nowiki>}}</nowiki></code> → '''{{#ifexist: Special:Watchlist | exists | doesn't exist }}'''
:<code><nowiki>{{#ifexist:</nowiki> {{#special:CheckUser}} | exists | doesn't exist <nowiki>}}</nowiki></code> → {{#ifexist: Special:Checkuser | '''exists''' (because the [[mw:Extension:Checkuser|Checkuser]] extension is installed on this wiki) | '''doesn't exist''' (because the [[mw:Extension:Checkuser|Checkuser]] extension is not installed on this wiki) }}
:<code><nowiki>{{#ifexist: MediaWiki:Copyright | exists | doesn't exist }}</nowiki></code> → {{#ifexist: MediaWiki:Copyright | '''exists''' (because [[{{ns:8}}:Copyright]] has been customized) | '''doesn't exist''' (because [[{{ns:8}}:Copyright]] has not been customized) }}

If a page checks a target using <code>#ifexist:</code>, then that page will appear in the [[{{#special:WhatLinksHere}}]] list for the target page. So if the code <code><nowiki>{{#ifexist:Foo }}</nowiki></code> were included live on this page ({{FULLPAGENAME}}), [[{{#special:WhatLinksHere}}/Foo]] will list {{FULLPAGENAME}}.

On wikis using a shared media repository, <code>#ifexist:</code> can be used to check if a file has been uploaded to the repository but not to the wiki itself:
:<code><nowiki>{{#ifexist:</nowiki> {{ns:File}}:Example.png <nowiki>| exists | doesn't exist }}</nowiki></code> → '''{{#ifexist: {{ns:File}}:Example.png | exists | doesn't exist }}'''
:<code><nowiki>{{#ifexist:</nowiki> Image:Example.png <nowiki>| exists | doesn't exist }}</nowiki></code> → '''{{#ifexist: Image:Example.png | exists | doesn't exist }}'''
:<code><nowiki>{{#ifexist:</nowiki> {{ns:-2}}:Example.png <nowiki>| exists | doesn't exist }}</nowiki></code> → '''{{#ifexist: {{ns:-2}}:Example.png | exists | doesn't exist }}'''

If a local description page has been created for the file, the result is '''exists''' for all of the above.
<code>#ifexist:</code> does not work with interwiki links.

==== ifexist limits ====
<code>#ifexist:</code> is considered an "expensive parser function"; only a limited number of which can be included on any one page (including functions inside transcluded templates). When this limit is exceeded, any further <code>#ifexist:</code> functions automatically return false, whether the target page exists or not, and the page is categorized into [[:Category:Pages with too many expensive parser function calls]]. The name of the [[Help:Tracking categories|tracking category]] may vary depending on the content language of your wiki.

For some use cases it is possible to emulate the ifexist effect with css, by using the selectors <code>a.new</code> (to select links to unexisting pages) or <code>a:not(.new)</code> (to select links to existing pages). Furthermore, since the number of expensive parser functions that can be used on a single page is controlled by <code>{[[mw:Manual:$wgExpensiveParserFunctionLimit|$wgExpensiveParserFunctionLimit]]</code>, one can also increase the limit in LocalSettings.php if needed.

====ifexist and wanted pages====
A page that does not exist and is tested for using #ifexist will end up on the [[Special:WantedPages | Wanted Pages]].

===#rel2abs===
This function converts a relative file path into an absolute filepath.
:<code><nowiki>{{#rel2abs:</nowiki> ''path'' <nowiki>}}</nowiki></code>
:<code><nowiki>{{#rel2abs:</nowiki> ''path'' <nowiki>|</nowiki> ''base path'' <nowiki>}}</nowiki></code>

Within the <code>path</code> input, the following syntax is valid:
*<code>.</code> → the current level
*<code>..</code> → go up one level
*<code>/foo</code> → go down one level into the subdirectory /foo

If the <code>base path</code> is not specified, the full page name of the page will be used instead:
:<code><nowiki>{{#rel2abs:</nowiki> /quok   | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></code> → '''{{#rel2abs: /quok | {{ns:12}}:Foo/bar/baz }}'''
:<code><nowiki>{{#rel2abs:</nowiki> ./quok  | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></code> → '''{{#rel2abs: ./quok | {{ns:12}}:Foo/bar/baz }}'''
:<code><nowiki>{{#rel2abs:</nowiki> ../quok | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></code> → '''{{#rel2abs: ../quok | {{ns:12}}:Foo/bar/baz }}'''
:<code><nowiki>{{#rel2abs:</nowiki> ../.    | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></code> → '''{{#rel2abs: ../. | {{ns:12}}:Foo/bar/baz }}'''

Invalid syntax, such as <code>/.</code> or <code>/./</code>, is ignored.
Since no more than two consecutive full stops are permitted, sequences such as these can be used to separate successive statements:
:<code><nowiki>{{#rel2abs:</nowiki> ../quok/.        | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></code> → '''{{#rel2abs: ../quok/. | {{ns:12}}:Foo/bar/baz }}'''
:<code><nowiki>{{#rel2abs:</nowiki> ../../quok       | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></code> → '''{{#rel2abs: ../../quok | {{ns:12}}:Foo/bar/baz }}'''
:<code><nowiki>{{#rel2abs:</nowiki> ../../../quok    | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></code> → '''{{#rel2abs: ../../../quok | {{ns:12}}:Foo/bar/baz }}'''
:<code><nowiki>{{#rel2abs:</nowiki> ../../../../quok | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></code> → '''{{#rel2abs: ../../../../quok | {{ns:12}}:Foo/bar/baz }}'''

===#switch===
''See also : [[wikipedia:Help:Switch parser function|Help:Switch parser function]]''

This function compares one input value against several test cases, returning an associated string if a match is found.
<pre>
<nowiki>{{#switch:</nowiki> ''comparison string''
 {{!}} ''case'' = ''result''
 {{!}} ''case'' = ''result''
 {{!}} ''...''
 {{!}} ''case'' = ''result''
 {{!}} ''default result''
<nowiki>}}</nowiki>
</pre>

Examples:
:<code><nowiki>{{#switch: baz | foo = Foo | baz = Baz | Bar }}</nowiki></code> → ''' {{#switch: baz | foo = Foo | baz = Baz | Bar }} '''
:<code><nowiki>{{#switch: foo | foo = Foo | baz = Baz | Bar }}</nowiki></code> → ''' {{#switch: foo | foo = Foo | baz = Baz | Bar }} '''
:<code><nowiki>{{#switch: zzz | foo = Foo | baz = Baz | Bar }}</nowiki></code> → ''' {{#switch: zzz | foo = Foo | baz = Baz | Bar }} '''

<nowiki>#</nowiki>switch with partial transclusion tags can affect a configuration file that enables an editor unfamiliar with template coding to view and edit configurable elements.

====Default====
The <code>''default result''</code> is returned if no <code>''case''</code> string matches the <code>''comparison string''</code>:
:<code><nowiki>{{#switch: test | foo = Foo | baz = Baz | Bar }}</nowiki></code> → ''' {{#switch: test | foo = Foo | baz = Baz | Bar }} '''

In this syntax, the default result must be the last parameter and must not contain a raw equals sign (an equals sign without <code><nowiki>{{}}</nowiki></code>).
If it does, it will be treated as a case comparison, and no text will display if no cases match.
This is because the default value has not been defined (is empty).
If a case matches however, its associated string will be returned.
:<code><nowiki>{{#switch: test | Bar | foo = Foo | baz = Baz }}</nowiki></code>&nbsp;→ ''' {{#switch: test | Bar | foo =Foo | baz =Baz }} '''<!-- do not remove the spaces between «''' {{» and «}} '''» -->
:<code><nowiki>{{#switch: test | foo = Foo | baz = Baz | B=ar }}</nowiki></code>&nbsp;→ ''' {{#switch: test | foo = Foo | baz = Baz | B=ar }} '''<!-- do not remove the spaces between «''' {{» and «}} '''» -->
:<code><nowiki>{{#switch: test | test = Foo | baz = Baz | B=ar }}</nowiki></code>&nbsp;→ ''' {{#switch: test | test = Foo | baz = Baz | B=ar }} '''<!-- do not remove the spaces between «''' {{» and «}} '''» -->

Alternatively, the default result may be explicitly declared with a <code>''case''</code> string of "<code>#default</code>".
<pre>
<nowiki>{{#switch:</nowiki> ''comparison string''
 {{!}} ''case'' = ''result''
 {{!}} ''case'' = ''result''
 {{!}} ''...''
 {{!}} ''case'' = ''result''
 {{!}} #default = ''default result''
<nowiki>}}</nowiki>
</pre>

Default results declared in this way may be placed anywhere within the function:
:<code><nowiki>{{#switch: test | foo = Foo | #default = Bar | baz = Baz }}</nowiki></code> → ''' {{#switch: test | foo = Foo | #default = Bar | baz = Baz }} '''

If the <code>''default''</code> parameter is omitted and no match is made, no <code>''result''</code> is returned:
:<code><nowiki>{{#switch: test | foo = Foo | baz = Baz }}</nowiki></code> → ''' {{#switch: test | foo = Foo | baz = Baz }} '''<!-- do not remove the spaces between «''' {{» and «}} '''» -->

====Grouping results====
It is possible to have 'fall through' values, where several <code>''case''</code> strings return the same <code>''result''</code> string. This minimizes duplication.

<pre>
<nowiki>{{#switch:</nowiki> ''comparison string''
 {{!}} ''case1'' = ''result1''
 {{!}} ''case2'' 
 {{!}} ''case3'' 
 {{!}} ''case4'' = ''result234''
 {{!}} ''case5'' = ''result5''
 {{!}} ''case6'' 
 {{!}} ''case7'' = ''result67''
 {{!}} #default = ''default result''
<nowiki>}}</nowiki>
</pre>

Here cases 2, 3 and 4 all return <code>''result234''</code>; cases 6 and 7 both return <code>''result67''</code>.
The "<code>#default = </code>" in the last parameter may be omitted in the above case.

==== Use with parameters ====
The function may be used with parameters as the test string. In this case, it is not necessary to place the pipe after the parameter name, because it is very unlikely that you will choose to set a case to be the string "<code><nowiki>{{{</nowiki>''parameter name''<nowiki>}}}</nowiki></code>". This is the value the parameter will default to if the pipe is absent and the parameter doesn't exist or have a value. See [[mw:Help:Parser functions in templates|Help:Parser functions in templates]].
:<code><nowiki>{{#switch: {{{1}}} | foo = Foo | baz = Baz | Bar }}</nowiki></code>

In the above case, if <code><nowiki>{{{1}}}</nowiki></code> equals <code>foo</code>, the function will return <code>Foo</code>. If it equals <code>baz</code>, the function will return <code>Baz</code>. If the parameter is empty or does not exist, the function will return <code>Bar</code>.

As in the section above, cases can be combined to give a single result.
:<code><nowiki>{{#switch: {{{1}}} | foo | zoo | roo = Foo | baz = Baz | Bar }}</nowiki></code>

Here, if <code><nowiki>{{{1}}}</nowiki></code> equals <code>foo</code>, <code>zoo</code> or <code>roo</code>, the function will return <code>Foo</code>. If it equals <code>baz</code>, the function will return <code>Baz</code>. If the parameter is empty or does not exist, the function will return <code>Bar</code>.

Additionally, the default result can be omitted if you do not wish to return anything if the test parameter value does not match any of the cases.
:<code><nowiki>{{#switch: {{{1}}} | foo = Foo | bar = Bar }}</nowiki></code>

In this case, the function returns an empty string unless <code><nowiki>{{{1}}}</nowiki></code> exists and equals <code>foo</code> or <code>bar</code>, in which case it returns <code>Foo</code> or <code>Bar</code>, respectively.
:<code><nowiki>{{#switch: {{{1}}} | foo | zoo | roo = Foo | baz = Baz | }}</nowiki></code>

If for some reason you decide to set a case as "<code><nowiki>{{{</nowiki>''parameter name''<nowiki>}}}</nowiki></code>", the function will return that case's result when the parameter doesn't exist or doesn't have a value. The parameter would have to exist and have a value other than the string "<code><nowiki>{{{</nowiki>''parameter name''<nowiki>}}}</nowiki></code>" to return the function's default result.
:(when <code><nowiki>{{{1}}}</nowiki></code> doesn't exist or is empty):
::<code><nowiki>{{#switch: {{{1}}} | {{{1}}} = Foo | baz = Baz | Bar }}</nowiki></code> → ''' Foo '''
:(when <code><nowiki>{{{1}}}</nowiki></code> has the value "<code>test</code>"):
::<code><nowiki>{{#switch: {{{1}}} | {{{1}}} = Foo | baz = Baz | Bar }}</nowiki></code> → ''' Bar '''
:(when <code><nowiki>{{{1}}}</nowiki></code> has the value "<code><nowiki>{{{1}}}</nowiki></code>"):
::<code><nowiki>{{#switch: {{{1}}} | {{{1}}} = Foo | baz = Baz | Bar }}</nowiki></code> → ''' Foo '''

In this hypothetical case, you would need to add the pipe to the parameter (<code><nowiki>{{{1</nowiki><span style="color:red; font-weight:bold">|</span><nowiki>}}}</nowiki></code>).

==See also==
* [[Help:Magic words]] help with other kinds of magic words.
* [[Help:Editing/Lua guide]] for the Lua guide (lua is invoked via the <code><nowiki>{{#invoke:}}</nowiki></code> parser function)
* [[mw:Help:Magic words|Help:Magic words]] at MediaWiki
* [[mw:Help:Extension:ParserFunctions|Help:Extension:ParserFunctions]] help for the ''ParserFunctions'' extension which adds additional parser functions (we have this installed)
* [[wikipedia:Help:Magic words|Help:Magic words]] at Wikipedia

{{Help}}