View source for Help:Parser Functions

{{help|[[IF]]}}{{cleanup}}

'''Parser Functions''' are extensions to the MediaWiki software, mainly allowing IF statements. These supplement the "[[Help:Magic words#Parser functions|magic words]]", which are already present in MediaWiki. All the parser functions provided by this extension take the form:
:<tt><nowiki>{{</nowiki>'''#functionname''': ''argument 1'' | ''argument 2'' | ''argument 3'' ... <nowiki>}}</nowiki></tt>

:''Read more at http://www.mediawiki.org/wiki/Help:Extension:ParserFunctions''

==#expr==

{| {{prettytable|style=float:right; width:30%; margin-left:1em;}}
|-
!{{hl1}} | Type
!{{hl1}} | Operators
|-
|{{hl2}} | Grouping (parentheses)
| style="word-spacing:0.5em; font-family:monospace; font-weight:bold;" | ( )
|-
|{{hl2}} | Numbers
| style="word-spacing:0.5em;" | <tt>'''1234.5'''</tt> <tt>'''e'''</tt>&nbsp;(2.718) <tt>'''pi'''</tt>&nbsp;(3.142)
|-
|{{hl2}} |
| binary operator <tt>'''e'''</tt>, unary +,-
|-
|{{hl2}} | Unary
| style="word-spacing:0.5em; font-family:monospace; font-weight:bold;" | not ceil trunc floor abs exp ln sin cos tan acos asin atan
|-
|{{hl2}} rowspan="3" | Binary
| <tt>'''^'''</tt>
|-
| style="word-spacing:0.5em; font-family:monospace; font-weight:bold;" | * / div mod
|-
| style="word-spacing:0.5em; font-family:monospace; font-weight:bold;" | + -
|-
|{{hl2}} | Round
| style="word-spacing:0.5em; font-family:monospace; font-weight:bold;" | round
|-
|{{hl2}} rowspan="3" | Logic
| style="word-spacing:0.5em; font-family:monospace; font-weight:bold;" | = != <> > < >= <=
|-
| style="word-spacing:0.5em; font-family:monospace; font-weight:bold;" | and
|-
| style="word-spacing:0.5em; font-family:monospace; font-weight:bold;" | or
|}

This function evaluates a mathematical expression and returns the calculated value.

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

The available operators are listed to the right, in order of precedence. See {{mediawiki|m: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 {{mediawiki|w:boolean algebra (logic)|boolean algebra}}, zero evaluates to <tt>false</tt> and any nonzero value, positive or negative, evaluates to <tt>true</tt>:

:<tt><nowiki>{{#expr: 1 and -1 }}</nowiki></tt> → '''{{#expr: 1 and -1 }}'''
:<tt><nowiki>{{#expr: 1 and 0 }}</nowiki></tt> → '''{{#expr: 1 and 0 }}'''

An empty input expression returns an empty string. Invalid expressions return one of several error messages, which can be caught using the <tt>[[##iferror|#iferror]]</tt> function:

:<tt><nowiki>{{#expr: }}</nowiki></tt> → ''' {{#expr: }}'''
:<tt><nowiki>{{#expr: 1+ }}</nowiki></tt> → '''{{#expr: 1+ }}'''
:<tt><nowiki>{{#expr: 1 foo 2 }}</nowiki></tt> → '''{{#expr: 1 foo 2 }}'''

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 by <tt><nowiki>{{formatnum:{{NUMBEROFUSERS}}|R}}</nowiki></tt>. This is especially important in some languages, where numerals are translated. For example, in Bengali, <nowiki>{{NUMBEROFUSERS}}</nowiki> produces ৩০,০৬১. 

:<tt><nowiki>{{#expr:{{NUMBEROFUSERS}}+100}}</nowiki></tt> → ''' {{#expr:{{NUMBEROFUSERS}}+100}}'''
:<tt><nowiki>{{#expr:{{formatnum:{{NUMBEROFUSERS}}|R}}+100}}</nowiki></tt> → '''{{#expr:{{formatnum:{{NUMBEROFUSERS}}|R}}+100}}'''



{{warning|The operator mod gives wrong results for some values of the second argument:
<!-- the following line now produces the correct value:
:<tt><nowiki>{{#expr: 123 mod (2^32-1)}}</nowiki></tt> → '''{{#expr: 123 mod (2^32-1)}}''' (should be 123)<br />
but see this one: -->
:<tt><nowiki>{{#expr: 123 mod (2^64-1)}}</nowiki></tt> → {{#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:
:<tt><nowiki>{{#expr: 20060618093259 mod 10000}}</nowiki></tt> → '''{{#expr: 20060618093259 mod 10000}}''' in most cases, but may occasionally give '''-6357'''. See {{bugzilla|6356}}.
-->
}}

=== Rounding ===

[http://php.net/manual/en/function.round.php 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:

: <code><nowiki>{{#expr: 9.876 round2 }}</nowiki></code> → {{#expr: 9.876 round2 }}
: <code><nowiki>{{#expr: (trunc1234) round trunc-2 }}</nowiki></code> → {{#expr: (trunc1234) round trunc-2 }}
: <code><nowiki>{{#expr: 4.5 round0 }}</nowiki></code> → {{#expr: 4.5 round0 }}
: <code><nowiki>{{#expr: -4.5 round0 }}</nowiki></code> → {{#expr: -4.5 round0 }}
: <code><nowiki>{{#expr: 46.857 round1.8 }}</nowiki></code> → {{#expr: 46.857 round1.8 }}
: <code><nowiki>{{#expr: 46.857 round-1.8 }}</nowiki></code> → {{#expr: 46.857 round-1.8 }}

==#if==

:<tt><nowiki>{{#if:</nowiki> ''test string'' | ''value if test string is not empty'' | ''value if test string is empty (or only white space)'' <nowiki>}}</nowiki></tt>

:<tt><nowiki>{{#if:</nowiki> first parameter | second parameter | third parameter <nowiki>}}</nowiki></tt>

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.

:<tt><nowiki>{{#if: | yes | no}}</nowiki></tt> → '''{{#if: | yes | no}}'''
:<tt><nowiki>{{#if: string | yes | no}}</nowiki></tt> → '''{{#if: string | yes | no}}'''
:<tt><nowiki>{{#if: &nbsp;&nbsp;&nbsp;&nbsp; | yes | no}}</nowiki></tt> → '''{{#if:        | yes | no}}'''
:<tt><nowiki>{{#if: </nowiki><br /><br /><br /><nowiki> | yes | no}}</nowiki></tt> → '''{{#if: 


| yes | no}}'''

The test string is always interpreted as pure text, so mathematical expressions are not evaluated:

:<tt><nowiki>{{#if: 1==2 | yes | no }}</nowiki></tt> → '''{{#if: 1==2 | yes | no}}'''
:<tt><nowiki>{{#if: 0 | yes | no }}</nowiki></tt> → '''{{#if: 0 | yes | no }}'''

Either or both the return values may be omitted:

:<tt><nowiki>{{#if: foo | yes }}</nowiki></tt> → ''' {{#if: foo | yes }}'''
:<tt><nowiki>{{#if: | yes }}</nowiki></tt> → ''' {{#if: | yes }}'''
:<tt><nowiki>{{#if: foo | | no}}</nowiki></tt> → ''' {{#if: foo | | no}}'''

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

==#ifeq==

This parser function compares two strings and determines whether they are identical.  

:<tt><nowiki>{{#ifeq:</nowiki> ''string 1'' <nowiki>|</nowiki> ''string 2'' <nowiki>|</nowiki> ''value if identical'' <nowiki>|</nowiki> ''value if different'' <nowiki>}}</nowiki></tt>

If both strings are valid numerical values, the strings are compared numerically:

:<tt><nowiki>{{#ifeq: 01 | 1 | equal | not equal}}</nowiki></tt> → '''{{#ifeq: 01 | 1 | equal | not equal}}''' 
:<tt><nowiki>{{#ifeq: 0 | -0 | equal | not equal}}</nowiki></tt> → '''{{#ifeq: 0 | -0 | equal | not equal}}'''
:<tt><nowiki>{{#ifeq: 1e3 | 1000 | equal | not equal}}</nowiki></tt> → '''{{#ifeq: 1e3 | 1000 | equal | not equal}}'''
:<tt><nowiki>{{#ifeq: {{#expr:10^3}} | 1000 | equal | not equal}}</nowiki></tt> → '''{{#ifeq: {{#expr:10^3}} | 1000 | equal | not equal}}'''

Otherwise the comparison is made as text; this comparison is case sensitive:

:<tt><nowiki>{{#ifeq: foo | bar | equal | not equal}}</nowiki></tt> → '''{{#ifeq: foo | bar | equal | not equal}}'''
:<tt><nowiki>{{#ifeq: foo | Foo | equal | not equal}}</nowiki></tt> → '''{{#ifeq: foo | Foo | equal | not equal}}'''
:<tt><nowiki>{{#ifeq: "01" | "1" | equal | not equal}}</nowiki></tt> → '''{{#ifeq: "01" | "1" | equal | not equal}}''' &nbsp;''(compare to similar example above, without the quotes)''
:<tt><nowiki>{{#ifeq: 10^3 | 1000 | equal | not equal}}</nowiki></tt> → '''{{#ifeq: 10^3 | 1000 | equal | not equal}}'''  &nbsp;''(compare to similar example above, with <tt>[[##expr|#expr]]</tt>)''

As a practical example, given an existing [[Help:Templates|template]] <tt>Template:Size</tt> used to set standard short and long sizes, defined as:

<pre>{{#ifeq: {{{1|}}} | short | 20 | 40}}</pre>

the following ensue:

:<tt><nowiki>{{size|short}}</nowiki></tt> → '''20'''
:<tt><nowiki>{{size|20}}</nowiki></tt> → '''40'''
:<tt><nowiki>{{size}}</nowiki></tt> → '''40'''

{{warning|Numerical comparisons with <tt>#ifeq</tt> and <tt>[[##switch|#switch]]</tt> are not equivalent to comparisons with <tt>[[##expr|#expr]]</tt>:

:<tt><nowiki>{{#ifeq: 12345678901234567 | 12345678901234568 | equal | not equal}}</nowiki></tt> → '''{{#ifeq: 12345678901234567 | 12345678901234568 | equal | not equal}}'''
:<tt><nowiki>{{#switch: 12345678901234567 | 12345678901234568 = equal | not equal}}</nowiki></tt> → '''{{#switch: 12345678901234567 | 12345678901234568 = equal | not equal}}'''

because PHP compares two numbers of type integer, whereas:

:<tt><nowiki>{{#ifexpr: 12345678901234567 = 12345678901234568 | equal | not equal}}</nowiki></tt> → '''{{#ifexpr: 12345678901234567 = 12345678901234568 | equal | not equal}}'''

because MediaWiki converts literal numbers in expressions to type float, which, for large integers like these, involves rounding.<br /><br />
}}

{{warning|Content inside parser tags (such as <tt><nowiki><nowiki></nowiki></tt>) is temporarily replaced by a unique code. This affects comparisons: 

:<tt><nowiki>{{#ifeq: &lt;nowiki>foo&lt;/nowiki> | &lt;nowiki>foo&lt;/nowiki> | equal | not equal}}</nowiki></tt> → '''{{#ifeq: <nowiki>foo</nowiki> | <nowiki>foo</nowiki> | equal | not equal}} '''
:<tt><nowiki>{{#ifeq: &lt;math>foo&lt;/math> | &lt;math>foo&lt;/math> | equal | not equal}}</nowiki></tt> → '''{{#ifeq: <math>foo</math> | <math>foo</math> | equal | not equal}} '''
:<tt><nowiki>{{#ifeq: {{</nowiki>[[Help:Magic words#Miscellaneous|#tag:]]<nowiki>math|foo}} | {{#tag:math|foo}} | equal | not equal}}</nowiki></tt> → '''{{#ifeq: {{#tag:math|foo}} | {{#tag:math|foo}} | equal | not equal}} '''
:<tt><nowiki>{{#ifeq: [[foo]] | [[foo]] | equal | not equal}}</nowiki></tt> → '''{{#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.
}}

==#iferror==

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

:<tt><nowiki>{{#iferror:</nowiki> ''test string'' <nowiki>|</nowiki> ''value if error'' <nowiki>|</nowiki> ''value if correct'' <nowiki>}}</nowiki></tt>

One or both of the return strings can be omitted.  If the <tt>''correct''</tt> string is omitted, the <tt>''test string''</tt> is returned if it is not erroneous. If the <tt>''error''</tt> string is also omitted, an empty string is returned on an error:

:<tt><nowiki>{{#iferror: {{#expr: 1 + 2 }} | error | correct }}</nowiki></tt> → '''{{#iferror: {{#expr: 1 + 2 }} | error | correct }}'''
:<tt><nowiki>{{#iferror: {{#expr: 1 + X }} | error | correct }}</nowiki></tt> → '''{{#iferror: {{#expr: 1 + X }} | error | correct }}'''
:<tt><nowiki>{{#iferror: {{#expr: 1 + 2 }} | error }}</nowiki></tt> → '''{{#iferror: {{#expr: 1 + 2 }} | error }}'''
:<tt><nowiki>{{#iferror: {{#expr: 1 + X }} | error }}</nowiki></tt> → '''{{#iferror: {{#expr: 1 + X }} | error }}'''
:<tt><nowiki>{{#iferror: {{#expr: 1 + 2 }} }}</nowiki></tt> → '''{{#iferror: {{#expr: 1 + 2 }} }}'''
:<tt><nowiki>{{#iferror: {{#expr: 1 + X }} }}</nowiki></tt> → '''&zwnj;{{#iferror: {{#expr: 1 + X }} }}'''
:<tt><nowiki>{{#iferror: <strong class="error">a</strong> | error | correct }}</nowiki></tt> → '''{{#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:

:<tt><nowiki>{{#ifexpr:</nowiki> ''expression'' <nowiki>|</nowiki> ''value if true'' <nowiki>|</nowiki> ''value if false'' <nowiki>}}</nowiki></tt>

The <tt>''expression''</tt> input is evaluated exactly as for [[##expr|<tt>#expr</tt>]] above, with the same operators being available.  The output is then evaluated as a boolean expression. 

An empty input expression evaluates to false:

:<tt><nowiki>{{#ifexpr: | yes | no}}</nowiki></tt> → '''{{#ifexpr: | yes | no}}'''

As mentioned above, zero evaluates to false and any nonzero value evaluates to true, so this function is equivalent to one using <tt>[[##ifeq|#ifeq]]</tt> and <tt>[[##expr|#expr]]</tt> only:

:<tt><nowiki>{{#ifeq: {{#expr: </nowiki>''expression''<nowiki> }} | 0 | </nowiki> ''value if false'' <nowiki>|</nowiki> ''value if true'' <nowiki>}}</nowiki></tt>

except for an empty or wrong input expression (an error message is treated as an ordinary string; it is not equal to zero, so we get <tt>''value if true''</tt>). 

Either or both the return values may be omitted; no output is given when the appropriate branch is left empty:

:<tt><nowiki>{{#ifexpr: 1 > 0 | yes }}</nowiki></tt> → '''{{#ifexpr: 1 > 0 | yes }}'''
:<tt><nowiki>{{#ifexpr: 1 < 0 | yes }}</nowiki></tt> → ''' {{#ifexpr: 1 < 0 | yes }}'''
:<tt><nowiki>{{#ifexpr: 0 = 0 | yes }}</nowiki></tt> → ''' {{#ifexpr: 0 = 0 | yes }}'''
:<tt><nowiki>{{#ifexpr: 1 > 0 | | no}}</nowiki></tt> → ''' {{#ifexpr: 1 > 0 | | no}}'''
:<tt><nowiki>{{#ifexpr: 1 < 0 | | no}}</nowiki></tt> → ''' {{#ifexpr: 1 < 0 | | no}}'''
:<tt><nowiki>{{#ifexpr: 1 > 0 }}</nowiki></tt> → ''' {{#ifexpr: 1 > 0 }}'''

==#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.

:<tt><nowiki>{{#ifexist:</nowiki> ''page title'' | ''value if exists'' | ''value if doesn't exist'' <nowiki>}}</nowiki></tt>

The function evaluates to <tt>true</tt> 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:Redirect|redirect]].  Only pages that are redlinked evaluate to false, including if the page used to exist but has been deleted.  

:<tt><nowiki>{{#ifexist:</nowiki> {{FULLPAGENAME}} | exists | doesn't exist <nowiki>}}</nowiki></tt> → '''{{#ifexist: {{FULLPAGENAME}} | exists | doesn't exist }}'''
:<tt><nowiki>{{#ifexist:</nowiki> XX{{FULLPAGENAME}}XX | exists | doesn't exist <nowiki>}}</nowiki></tt> → '''{{#ifexist: XX{{FULLPAGENAME}}XX | exists | doesn't exist }}'''

The function evaluates to true for [[Help:System messages|system messages]] that have been customised, and for [[Help:Special pages|special pages]] that are defined by the software.  

:<tt><nowiki>{{#ifexist:</nowiki> {{#special:Watchlist}} | exists | doesn't exist <nowiki>}}</nowiki></tt> → '''{{#ifexist: Special:Watchlist | exists | doesn't exist }}'''
:<tt><nowiki>{{#ifexist:</nowiki> {{#special:CheckUser}} | exists | doesn't exist <nowiki>}}</nowiki></tt> → {{#ifexist: Special:Checkuser | '''exists''' (because the {{mediawiki|Extension:Checkuser|CheckUser extension}} is installed on this wiki) | '''doesn't exist''' (because the {{mediawiki|Extension:Checkuser|CheckUser extension}} is not installed on this wiki) }}
:<tt><nowiki>{{#ifexist: MediaWiki:Copyright | exists | doesn't exist }}</nowiki></tt> → {{#ifexist: MediaWiki:Copyright | '''exists''' (because [[{{ns:8}}:Copyright]] has been customised) | '''doesn't exist''' (because [[{{ns:8}}:Copyright]] has not been customised) }}

<tt>#ifexist:</tt> 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, the page is categorised into [[:Category:{{MediaWiki:expensive-parserfunction-category}}]], and any further <tt>#ifexist:</tt> functions automatically return false, whether the target page exists or not.

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

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

<tt>#ifexist:</tt> does not work with interwiki links.

Note: When testing for <code>#ifexist:</code>, test for the path to the filename not as a wikilink.

==#rel2abs==

This function converts a relative file path into an absolute filepath.

:<tt><nowiki>{{#rel2abs:</nowiki> ''path'' <nowiki>}}</nowiki></tt>
:<tt><nowiki>{{#rel2abs:</nowiki> ''path'' <nowiki>|</nowiki> ''base path'' <nowiki>}}</nowiki></tt>

Within the <tt>path</tt> 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 <tt>base path</tt> is not specified, the full page name of the page will be used instead:

:<tt><nowiki>{{#rel2abs:</nowiki> /quok | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></tt> → '''{{#rel2abs: /quok | {{ns:12}}:Foo/bar/baz }}
:<tt><nowiki>{{#rel2abs:</nowiki> ./quok | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></tt> → '''{{#rel2abs: ./quok | {{ns:12}}:Foo/bar/baz }}
:<tt><nowiki>{{#rel2abs:</nowiki> ../quok | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></tt> → '''{{#rel2abs: ../quok | {{ns:12}}:Foo/bar/baz }}
:<tt><nowiki>{{#rel2abs:</nowiki> ../. | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></tt> → '''{{#rel2abs: ../. | {{ns:12}}:Foo/bar/baz }}

Invalid syntax, such as <tt>/.</tt> or <tt>/./</tt>, is ignored. Since no more than two consecutive full stops are permitted, sequences such as these can be used to separate successive statements: 

:<tt><nowiki>{{#rel2abs:</nowiki> ../quok/. | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></tt> → '''{{#rel2abs: ../quok/. | {{ns:12}}:Foo/bar/baz }}
:<tt><nowiki>{{#rel2abs:</nowiki> ../../quok | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></tt> → '''{{#rel2abs: ../../quok | {{ns:12}}:Foo/bar/baz }}
:<tt><nowiki>{{#rel2abs:</nowiki> ../../../quok | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></tt> → '''{{#rel2abs: ../../../quok | {{ns:12}}:Foo/bar/baz }}
:<tt><nowiki>{{#rel2abs:</nowiki> ../../../../quok | {{ns:12}}:Foo/bar/baz <nowiki>}}</nowiki></tt> → '''{{#rel2abs: ../../../../quok | {{ns:12}}:Foo/bar/baz }}

==#switch==
This function compares one input value against several test cases, returning an associated string if a match is found. 

 <nowiki>{{#switch:</nowiki> ''comparison string''
  | ''case'' = ''result''
  | ''case'' = ''result''
  | ''...''
  | ''case'' = ''result''
  | ''default result''
 <nowiki>}}</nowiki>

Example:

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

<nowiki>#</nowiki>switch allows an editor to add information in one template and this information will be visible in several other templates which all have different formatting.

===Default===
The <tt>''default result''</tt> is returned if no <tt>''case''</tt> string matches the <tt>''comparison string''</tt>:

:<tt><nowiki>{{#switch: test | foo = Foo | baz = Baz | Bar }}</nowiki></tt> → ''' {{#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.

:<tt><nowiki>{{#switch: test | Bar | foo = Foo | baz = Baz }}</nowiki></tt>&nbsp;→ ''' {{#switch: test | Bar | foo = Foo | baz = Baz }} '''<!-- do not remove the spaces between «''' {{» and «}} '''» -->
:<tt><nowiki>{{#switch: test | foo = Foo | baz = Baz | B=ar }}</nowiki></tt>&nbsp;→ ''' {{#switch: test | foo = Foo | baz = Baz | B=ar }} '''<!-- do not remove the spaces between «''' {{» and «}} '''» -->

Alternatively, the default result may be explicitly declared with a <tt>''case''</tt> string of "<tt>#default</tt>".

 <nowiki>{{#switch:</nowiki> ''comparison string''
  | ''case'' = ''result''
  | ''case'' = ''result''
  | ''...''
  | ''case'' = ''result''
  | ''#default = default result''
 <nowiki>}}</nowiki>

Default results declared in this way may be placed anywhere within the function:

:<tt><nowiki>{{#switch: test | foo = Foo | #default = Bar | baz = Baz }}</nowiki></tt> → ''' {{#switch: test | foo = Foo | #default = Bar | baz = Baz }} '''

If the <tt>''default''</tt> parameter is omitted and no match is made, no <tt>''result''</tt> is returned:

:<tt><nowiki>{{#switch: test | foo = Foo | baz = Baz }}</nowiki></tt> → ''' {{#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 <tt>''case''</tt> strings return the same <tt>''result''</tt> string. This minimizes duplication.

 <nowiki>{{#switch:</nowiki> ''comparison string''
  | ''case1'' = ''result1''
  | ''case2'' 
  | ''case3'' 
  | ''case4'' = ''result2''
  | ''case5'' = ''result3''
  | ''case6'' 
  | ''case7'' = ''result4''
  | ''#default = default result''
 <nowiki>}}</nowiki>

Here cases 2, 3 and 4 all return <tt>''result2''</tt>; cases 6 and 7 both return <tt>''result4''</tt>

===Comparison behaviour===
As with <tt>[[##ifeq|#ifeq]]</tt>, the comparison is made numerically if both the comparison string and the case string being tested are numeric; or as a case-sensitive string otherwise:

:<tt><nowiki>{{#switch: 0 + 1 | 1 = one | 2 = two | three}}</nowiki></tt>&nbsp;→ '''{{#switch: 0 + 1 | 1 = one | 2 = two | three}}'''
:<tt><nowiki>{{#switch: {{#expr: 0 + 1}} | 1 = one | 2 = two | three}}</nowiki></tt>&nbsp;→ '''{{#switch: {{#expr: 0 + 1}} | 1 = one | 2 = two | three}}'''

:<tt><nowiki>{{#switch: a | a = A | b = B | C}}</nowiki></tt>&nbsp;→ '''{{#switch: a | a = A | b = B | C}}'''
:<tt><nowiki>{{#switch: A | a = A | b = B | C}}</nowiki></tt>&nbsp;→ '''{{#switch: A | a = A | b = B | C}}'''

A <tt>''case''</tt> string may be empty:
:<tt><nowiki>{{#switch: | = Nothing | foo = Foo | Something }}</nowiki></tt> → '''{{#switch: | = Nothing | foo = Foo | Something }}'''
Once a match is found, subsequent <tt>''cases''</tt> are ignored:
:<tt><nowiki>{{#switch: b | f = Foo | b = Bar | b = Baz | }}</nowiki></tt> → '''{{#switch: b | f = Foo | b = Bar | b = Baz | }}'''

{{warning|Numerical comparisons with <code>#switch</code> and <code>#ifeq</code> are not equivalent with comparisons in expressions (see also above):

:<tt><nowiki>{{#switch: 12345678901234567 | 12345678901234568 = A | B}}</nowiki></tt>&nbsp;→ '''{{#switch: 12345678901234567 | 12345678901234568 = A | B}}'''
:<tt><nowiki>{{#ifexpr: 12345678901234567 = 12345678901234568 | A | B}}</nowiki></tt>&nbsp;→ '''{{#ifexpr: 12345678901234567 = 12345678901234568 | A | B}}'''
}}

===Raw equal signs===
"Case" strings cannot contain raw equals signs. To work around this, create a template {{tl|{{=}}}} containing a single equals sign: <tt>=</tt>.

Example:

:<tt><nowiki>{{#switch: 1=2</nowiki></tt>
:<tt><nowiki>&nbsp;| 1=2 = raw</nowiki></tt>
:<tt><nowiki>&nbsp;| 1&lt;nowiki>=&lt;/nowiki>2 = nowiki</nowiki></tt>
:<tt><nowiki>&nbsp;| 1&amp;#61;2 = html</nowiki></tt>
:<tt><nowiki>&nbsp;| 1{{=}}2 = template</nowiki></tt>
:<tt><nowiki>&nbsp;| default }}</nowiki></tt> → '''{{#switch: 1=2 | 1=2 = raw | 1<nowiki>=</nowiki>2 = nowiki | 1&#61;2 = html | 1{{=}}2 = template | default }}'''

{{note}}
For a simple real life example of the use of this function, check {{mediawiki|w:Template:NBA color|Template:NBA color}}. Two complex examples can be found at {{mediawiki|Template:Extension}} and [http://en.wikipedia.org/wiki/Template:BOTREQ Template:BOTREQ].

==#time==

{| {{prettytable|style=float:right; width:40%; font-size:90%; line-height:1.25em; margin-left:1em;}}
! {{hl1}} | Code 
! {{hl1}} | Description
! {{hl1}} | Current output <br/><small>([{{fullurl:Help:Extension:ParserFunctions|action=purge}} Purge this page's cache] to update)</small>
|-
! {{hl2}} colspan="3"| Year
|-
| style="text-align:center; font-family:monospace;" | Y
| 4-digit year.
| style="text-align:center;" | {{#time:Y}}
|-
| style="text-align:center; font-family:monospace;" | y
| 2-digit year.
| style="text-align:center;" | {{#time:y}}
|-
| style="text-align:center; font-family:monospace;" | L
| 1 or 0 whether it's a leap year or not.
| style="text-align:center;" | {{#time:L}}
|-
| style="text-align:center; font-family:monospace;" | o ¹
| ISO-8601 year number. ²
| style="text-align:center;" | {{#time:o}} ³
|-
| colspan="3" style="font-size:88%" |
¹ Requires PHP 5.1.0 and newer and [[rev:45208]].<br />
² This has the same value as Y, except that if the ISO week number (W) belongs to the previous or next year, that year is used instead.<br />
³ Will output literal ''o'' if ¹ not fulfilled.
|-
! {{hl2}} colspan="3"| Month
|-
| style="text-align:center; font-family:monospace;" | n
| Month index, not zero-padded.
| style="text-align:center;" | {{#time:n}}
|-
| style="text-align:center; font-family:monospace;" | m
| Month index, zero-padded.
| style="text-align:center;" | {{#time:m}}
|-
| style="text-align:center; font-family:monospace;" | M
| An abbreviation of the month name, in the site language.
| style="text-align:center;" | {{#time:M}}
|-
| style="text-align:center; font-family:monospace;" | F
| The full month name in the site language.
| style="text-align:center;" | {{#time:F}}
|-
| style="text-align:center; font-family:monospace;" | xg
| Output the full month name in the genitive form for site languages that distinguish between genitive and nominative forms.
| For Polish:

(nominative) 

<tt><nowiki>{{#time:d F Y|20 June 2010}|pl}}</nowiki></tt> → {{#time:d F Y|20 June 2010|pl}}

(genitive) 

<tt><nowiki>{{#time:d xg Y|20 June 2010|pl}}</nowiki></tt> → {{#time:d xg Y|20 June 2010|pl}}
|-
! {{hl2}} colspan="3"| Week
|-
| style="text-align:center; font-family:monospace;" | W
| ISO 8601 week number, zero-padded.
| style="text-align:center;" | {{#time:W}}
|-
! {{hl2}} colspan="3"| Day
|-
| style="text-align:center; font-family:monospace;" | j
| Day of the month, not zero-padded.
| style="text-align:center;" | {{#time:j}}
|-
| style="text-align:center; font-family:monospace;" | d
| Day of the month, zero-padded.
| style="text-align:center;" | {{#time:d}}
|-
| style="text-align:center; font-family:monospace;" | z
| Day of the year (January&nbsp;1 = 0).<br>{{note}} To get the ISO day of the year add 1. 
| style="text-align:center;" | {{#time:z}}
|-
| style="text-align:center; font-family:monospace;" | D
| An abbreviation for the day of the week. Rarely internationalised.
| style="text-align:center;" | {{#time:D}}
|-
| style="text-align:center; font-family:monospace;" | l
| The full weekday name. Rarely internationalised.
| style="text-align:center;" | {{#time:l}}
|-
| style="text-align:center; font-family:monospace;" | N
| ISO 8601 day of the week (Monday = 1, Sunday = 7).
| style="text-align:center;" | {{#time:N}}
|-
| style="text-align:center; font-family:monospace;" | w
| Number of the day of the week (Sunday = 0, Saturday = 6).
| style="text-align:center;" | {{#time:w}}
|-
! {{hl2}} colspan="3"| Hour
|-
| style="text-align:center; font-family:monospace;" | a
| "am" during the morning (00:00:00 → 11:59:59), "pm" otherwise (12:00:00 → 23:59:59).
| style="text-align:center;" | {{#time:a}}
|-
| style="text-align:center; font-family:monospace;" | A
| Uppercase version of <tt>a</tt> above.
| style="text-align:center;" | {{#time:A}}
|-
| style="text-align:center; font-family:monospace;" | g
| Hour in 12-hour format, not zero-padded.
| style="text-align:center;" | {{#time:g}}
|-
| style="text-align:center; font-family:monospace;" | h
| Hour in 12-hour format, zero-padded.
| style="text-align:center;" | {{#time:h}}
|-
| style="text-align:center; font-family:monospace;" | G
| Hour in 24-hour format, not zero-padded.
| style="text-align:center;" | {{#time:G}}
|-
| style="text-align:center; font-family:monospace;" | H
| Hour in 24-hour format, zero-padded.
| style="text-align:center;" | {{#time:H}}
|-
! {{hl2}} colspan="3"| Minutes and seconds
|-
| style="text-align:center; font-family:monospace;" | i
| Minutes past the hour, zero-padded.
| style="text-align:center;" | {{#time:i}}
|-
| style="text-align:center; font-family:monospace;" | s
| Seconds past the minute, zero-padded.
| style="text-align:center;" | {{#time:s}}
|-
| style="text-align:center; font-family:monospace;" | U
| Seconds since January 1 1970 00:00:00 GMT.
| style="text-align:center;" | {{#time:U}}
|-
! {{hl2}} colspan="3"| Miscellaneous
|-
| style="text-align:center; font-family:monospace;" | t
| Number of days in the current month.
| style="text-align:center;" | {{#time:t}}
|-
| style="text-align:center; font-family:monospace;" | c
| ISO 8601 formatted date, equivalent to <tt><nowiki>Y-m-dTH:i:s+00:00</nowiki></tt>.
| style="font-size:75%;" | {{#time:c}}
|-
| style="text-align:center; font-family:monospace;" | r
| RFC 5322 formatted date, equivalent to <tt><nowiki>D, j M Y H:i:s +0000</nowiki></tt>, with weekday name and month name not internationalised.
| style="font-size:75%;" | {{#time:r}}
|-
! {{hl2}} colspan="3" | Non-Gregorian calendars
|-
! {{hl3}} colspan="3" | Islamic
|-
| style="text-align:center; font-family:monospace;" |  xmj
| Day of the month.
| {{#time:xmj}}
|-
| style="text-align:center; font-family:monospace;" |  xmF
| Full month name.
| {{#time:xmF}}
|-
| style="text-align:center; font-family:monospace;" |  xmn 
| Month index.
| {{#time:xmn}}
|-
| style="text-align:center; font-family:monospace;" |  xmY
| Full year.
| {{#time:xmY}}
|-
! {{hl3}} colspan="3" | Iranian
|-
| style="text-align:center; font-family:monospace;" |  xij
| Day of the month.
| {{#time:xij}}
|-
| style="text-align:center; font-family:monospace;" |  xiF
| Full month name.
| {{#time:xiF}}
|-
| style="text-align:center; font-family:monospace;" |  xin 
| Month index.
| {{#time:xin}}
|-
| style="text-align:center; font-family:monospace;" |  xiY
| Full year.
| {{#time:xiY}}
|-
! {{hl3}} colspan="3" | Hebrew
|-
| style="text-align:center; font-family:monospace;" |  xjj 
| Day of the month.
| {{#time:xjj}}
|-
| style="text-align:center; font-family:monospace;" |  xjF
| Full month name.
| {{#time:xjF}}
|-
| style="text-align:center; font-family:monospace;" |  xjt
| Number of days in month.
| {{#time:xjt}}
|-
| style="text-align:center; font-family:monospace;" |  xjx 
| Genitive form of the month name.
| {{#time:xjx}}
|-
| style="text-align:center; font-family:monospace;" |  xjn 
| Month number.
| {{#time:xjn}}
|-
| style="text-align:center; font-family:monospace;" |  xjY 
| Full year.
| {{#time:xjY}}
|-
! {{hl3}} colspan="3" | Thai solar
|-
| style="text-align:center; font-family:monospace;" |  xkY 
| Full year.
| {{#time:xkY}}
|-
! {{hl3}} colspan="3" | Minguo/Juche year
|-
| style="text-align:center; font-family:monospace;" | xoY 
| Full year.
| {{#time:xoY}}
|-
! {{hl3}} colspan="3" | Japanese nengo
|-
| style="text-align:center; font-family:monospace;" | xtY 
| Full year.
| {{#time:xtY}}
|-
! {{hl2}} colspan="3" | Flags
|-
| style="text-align:center; font-family:monospace;" |  xn
| Format the next numeric code as a raw ASCII number. 
|In the Hindi language, <tt><nowiki>{{#time:H, xnH}}</nowiki></tt> produces ०६, 06.
|-
| style="text-align:center; font-family:monospace;" |  xN
| colspan="2" | Like <tt>xn</tt>, but as a toggled flag, which endures until the end of the string or until the next appearance of <tt>xN</tt> in the string.
|-
| style="text-align:center; font-family:monospace;" |  xr
| Format the next number as a roman numeral. Only works for numbers up to 3000.
| <tt><nowiki>{{#time:xrY}}</nowiki></tt> → {{#time:xrY}}
|-
| style="text-align:center; font-family:monospace;" |  xh
| Format the next number as a Hebrew numeral.
| <tt><nowiki>{{#time:xhY}}</nowiki></tt> → {{#time:xhY}}
|}

This parser function takes a date and/or time (in the Gregorian calendar) and formats it according to the syntax given. A date/time object can be specified; the default is the value of the [[Help:Magic words#Date & time|magic word]] <tt><nowiki>{{CURRENTTIMESTAMP}}</nowiki></tt> &ndash; that is, the time the page was last rendered into HTML.  

:<tt><nowiki>{{#time:</nowiki> ''format string'' <nowiki>}}</nowiki></tt>
:<tt><nowiki>{{#time:</nowiki> ''format string'' <nowiki>|</nowiki> ''date/time object'' <nowiki>}}</nowiki></tt>
:<tt><nowiki>{{#time:</nowiki> ''format string'' <nowiki>|</nowiki> ''date/time object'' <nowiki>|</nowiki> ''language code'' <nowiki>}}</nowiki></tt>

The list of accepted formatting codes is given in the table to the right. Any character in the formatting string that is not recognised is passed through unaltered; this applies also to blank spaces (the system does not need them for interpreting the codes). There are also two ways to escape characters within the formatting string:
#A backslash followed by a formatting character is interpreted as a single literal character
#Characters enclosed in double quotes are considered literal characters, and the quotes are removed.
In addition, the digraph <tt>xx</tt> is interpreted as a single literal "x".  

:<tt><nowiki>{{#time: Y-m-d }}</nowiki></tt> → '''{{#time: Y-m-d }}'''
:<tt><nowiki>{{#time: [[Y]] m d }}</nowiki></tt> → '''{{#time: [[Y]] m d }}'''
:<tt><nowiki>{{#time: [[Y (year)]] }}</nowiki></tt> → '''{{#time: [[Y (year)]] }}'''
:<tt><nowiki>{{#time: [[Y "(year)"]] }}</nowiki></tt> → '''{{#time: [[Y "(year)"]] }}'''
:<tt><nowiki>{{#time: i's" }}</nowiki></tt> → '''{{#time: i's" }}'''

The <tt>''date/time object''</tt> can be in any format accepted by PHP's [http://www.php.net/manual/en/function.strtotime.php strtotime()] function. Both absolute (eg <tt>20 December 2000</tt>) and relative (eg <tt>+20 hours</tt>) times are accepted.  

<tt><nowiki>{{#time: r|now}}</nowiki></tt> → '''{{#time: r|now}}<br />
<tt><nowiki>{{#time: r|+2 hours}}</nowiki></tt> → '''{{#time: r|+2 hours}}<br />
<tt><nowiki>{{#time: r|now + 2 hours}}</nowiki></tt> → '''{{#time: r|now + 2 hours}}<br />

The ''language code'' in [[w:en:ISO 639-3|ISO 639-3]] (?) allows the string to be displayed in the chosen language
<tt><nowiki>{{#time:d F Y|1988-02-28|nl}}</nowiki></tt> → '''{{#time:d F Y|1988-02-28|nl}}<br />
<tt><nowiki>{{#time:l|now|uk}}</nowiki></tt> → '''{{#time:l|now|uk}}<br />
<tt><nowiki>{{#time:d xg Y|20 June 2010|pl}}</nowiki></tt> → '''{{#time:d xg Y|20 June 2010|pl}}<br />

If you've calculated a Unix timestamp, you may use it in date calculations by pre-pending an <tt>@</tt> symbol.

<tt><nowiki>{{#time: U | now }}</nowiki></tt> → '''{{#time: U | now}}<br />
<tt><nowiki>{{#time: r|@</nowiki>{{#time: U}}<nowiki>}}</nowiki></tt> → '''{{#time: r| @{{#time:U}} }}<br />

{{warning|The range of acceptable input is 1 January 0111 → 31 December 9999. For the years 100 through 110 the output is inconsistent, Y and leap years are like the years 100-110, r, D, l and U are like interpreting these years as 2000-2010.<br />
<tt><nowiki>{{#time: d F Y | 29 Feb 0100 }}</nowiki></tt> → '''{{#time: d F Y | 29 Feb 0100 }}'''<br /> (correct, no leap year), but<br />
<tt><nowiki>{{#time: r | 29 Feb 0100 }}</nowiki></tt> → '''{{#time: r | 29 Feb 0100 }}''' (wrong, even if 100 is interpreted as 2000, because that is a leap year)<br />
<tt><nowiki>{{#time: d F Y | 15 April 10000 }}</nowiki></tt> → '''{{#time: d F Y | 15 April 10000 }}<br />
<tt><nowiki>{{#time: r | 10000-4-15 }}</nowiki></tt> → '''{{#time: r | 10000-4-15 }}

Year numbers 0-99 are interpreted as 2000-2069 and 1970-1999, even when written with leading zeros:<br />
<tt><nowiki>{{#time: d F Y | 1 Jan 0069 }}</nowiki></tt> → '''{{#time: d F Y | 1 Jan 0069 }}'''<br /><br />
<tt><nowiki>{{#time: d F Y | 1 Jan 0070 }}</nowiki></tt> → '''{{#time: d F Y | 1 Jan 0070 }}'''

The weekday is supplied for the years 100-110 and from 1753, for the years 111-1752 the r-output shows "Unknown" and the l-output "<>". As a consequence, the r-output is not accepted as input for these years.}}

Full or partial absolute dates can be specified; the function will "fill in" parts of the date that are not specified using the ''current'' values:

:<tt><nowiki>{{#time: Y | January 1 }}</nowiki></tt> → '''{{#time: Y | January 1 }}

{{warning|The fill-in feature is not consistent; some parts are filled in using the current values, others are not:<br />
<tt><nowiki>{{#time: Y m d H:i:s | June }}</nowiki></tt> → '''{{#time: Y m d H:i:s | June }} <small>Gives the start of the day, but the current day of the month and the current year.</small>
<tt><nowiki>{{#time: Y m d H:i:s | 2003 }}</nowiki></tt> → '''{{#time: Y m d H:i:s | 2003 }} <small>Gives the start of the day, but the current day of the year.</small>
}}

With [[Special:Code/MediaWiki/86805|MediaWiki r86805 - Code Review]], a four-digit number is always interpreted as a year, never as hours and minutes:<br />
<tt><nowiki>{{#time: Y m d H:i:s | 1959 }}</nowiki></tt> → '''{{#time: Y m d H:i:s | 1959 }} 

A six-digit number is interpreted as hours, minutes and seconds if possible, but otherwise as an error (not, for instance, a year and month):<br />
<tt><nowiki>{{#time: Y m d H:i:s | 195909 }}</nowiki></tt> → '''{{#time: Y m d H:i:s | 195909 }} <small>Input is treated as a time rather than a year+month code.</small><br />
<tt><nowiki>{{#time: Y m d H:i:s | 196009 }}</nowiki></tt> → '''{{#time: Y m d H:i:s | 196009 }} <small>Although 19:60:09 is not a valid time, 196009 is not interpreted as September 1960.</small><br />

The function performs a certain amount of date mathematics:

:<tt><nowiki>{{#time: d F Y | January 0 2008 }}</nowiki></tt> → '''{{#time: d F Y | January 0 2008 }}
:<tt><nowiki>{{#time: d F | January 32 }}</nowiki></tt> → '''{{#time: d F | January 32 }}
:<tt><nowiki>{{#time: d F | February 29 2008 }}</nowiki></tt> → '''{{#time: d F | February 29 2008 }}
:<tt><nowiki>{{#time: d F | February 29 2007 }}</nowiki></tt> → '''{{#time: d F | February 29 2007 }}
:<tt><nowiki>{{#time:Y-F|now -1 months}}</nowiki></tt> → '''{{#time:Y-F|now -1 months}}

The total length of the format strings of the calls of <code>#time</code> is limited to 6000 characters [https://gerrit.wikimedia.org/r/gitweb?p=mediawiki/extensions/ParserFunctions.git;a=blob;f=ParserFunctions_body.php;hb=HEAD].

<br clear="all" />

==#timel==
This function is identical to <tt><nowiki>{{#time: ... }}</nowiki></tt>, except that it uses the local time of the wiki (as set in {{mediawiki|manual:$wgLocaltimezone|$wgLocaltimezone}}) when no date is given.

:<tt><nowiki>{{#time: Y-m-d }}</nowiki></tt> → '''{{#time: Y-m-d }}'''
:<tt><nowiki>{{#timel: Y-m-d }}</nowiki></tt> → '''{{#timel: Y-m-d }}'''
:<tt><nowiki>{{#time: Y F d h:i:s}}</nowiki></tt> → '''{{#time: Y F d h:i:s}}'''
:<tt><nowiki>{{#timel: Y F d h:i:s}}</nowiki></tt> → '''{{#timel: Y F d h:i:s}}'''

==#titleparts==

This function separates a pagetitle into segments based on slashes, then returns some of those segments as output.

:<tt><nowiki>{{#titleparts:</nowiki> ''pagename'' <nowiki>|</nowiki> ''number of segments to return'' <nowiki>|</nowiki> ''first segment to return'' <nowiki>}}</nowiki></tt> 

If the <tt>number of segments</tt> parameter is not specified, it defaults to "0", which returns ''all'' the segments.  If the <tt>first segment</tt> parameter is not specified or is "0", it defaults to "1":

:<tt><nowiki>{{#titleparts:</nowiki> <span style="color:blue;">{{ns:1}}:Foo/bar/baz/quok</span> <nowiki>}}</nowiki></tt> → '''{{#titleparts: {{ns:1}}:Foo/bar/baz/quok }}'''
:<tt><nowiki>{{#titleparts:</nowiki><span style="color:blue;"> {{ns:1}}:Foo</span>/bar/baz/quok <nowiki>| 1 }}</nowiki></tt> → '''{{#titleparts: {{ns:1}}:Foo/bar/baz/quok | 1 }}'''
:<tt><nowiki>{{#titleparts:</nowiki> <span style="color:blue;">{{ns:1}}:Foo/bar</span>/baz/quok <nowiki>| 2 }}</nowiki></tt> → '''{{#titleparts: {{ns:1}}:Foo/bar/baz/quok | 2 }}'''
:<tt><nowiki>{{#titleparts:</nowiki> {{ns:1}}:Foo/<span style="color:blue;">bar/baz</span>/quok <nowiki>| 2 | 2 }}</nowiki></tt> → '''{{#titleparts: {{ns:1}}:Foo/bar/baz/quok | 2 | 2 }}'''
:<tt><nowiki>{{#titleparts:</nowiki> {{ns:1}}:Foo/<span style="color:blue;">bar/baz/quok</span> <nowiki>| | 2 }}</nowiki></tt> → '''{{#titleparts: {{ns:1}}:Foo/bar/baz/quok | | 2 }}'''

Negative values are accepted for both values.  Negative values for <tt>number of segments</tt> effectively 'strips' segments from the end of the string. Negative values for <tt>first segment</tt> translates to "add this value to the total number of segments", loosely equivalent to "count from the right":

:<tt><nowiki>{{#titleparts:</nowiki> <span style="color:blue;">{{ns:1}}:Foo/bar/baz</span>/quok <nowiki>| -1 }}</nowiki></tt> → '''{{#titleparts: {{ns:1}}:Foo/bar/baz/quok | -1 }}''' <small>Strips one segment from the end of the string</small>
:<tt><nowiki>{{#titleparts:</nowiki> {{ns:1}}:Foo/bar/baz/quok <nowiki>| -4 }}</nowiki></tt> → '''{{#titleparts: {{ns:1}}:Foo/bar/baz/quok | -4 }} ''' <small>Strips all 4 segments from the end of the string</small>
:<tt><nowiki>{{#titleparts:</nowiki> {{ns:1}}:Foo/bar/baz/quok <nowiki>| -5 }}</nowiki></tt> → '''{{#titleparts: {{ns:1}}:Foo/bar/baz/quok | -5 }} ''' <small>Strips 5 segments from the end of the string (more than exist)</small>
:<tt><nowiki>{{#titleparts:</nowiki> {{ns:1}}:Foo/bar/baz/<span style="color:blue;">quok</span> <nowiki>| | -1 }}</nowiki></tt> → ''' {{#titleparts: {{ns:1}}:Foo/bar/baz/quok | | -1 }}'''
:<tt><nowiki>{{#titleparts:</nowiki> {{ns:1}}:Foo/<span style="color:blue;">bar/baz</span>/quok <nowiki>| -1 | 2 }}</nowiki></tt> → ''' {{#titleparts: {{ns:1}}:Foo/bar/baz/quok | -1 | 2 }}''' <small>Strips one segment from the end of the string, then returns the second segment and beyond</small>

The string is split a maximum of 25 times; further slashes are ignored and the 25th element will contain the rest of the string. The string is also limited to 255 characters, as it is treated as a [[Manual:Page table#Schema summary|page title]]:

:<tt><nowiki>{{#titleparts:</nowiki> a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/<span style="color:blue;">y/z/aa/bb/cc/dd/ee</span> <nowiki>| 1 | 25 }}</nowiki></tt> → '''{{#titleparts: a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/aa/bb/cc/dd/ee | 1 | 25 }}'''

If for whatever reason you needed to push this function to its limit, although very unlikely, it is possible to bypass the 25 split limit by nesting function calls:

:<tt><nowiki>{{#titleparts: {{#titleparts:</nowiki> a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/<span style="color:blue;">z</span>/aa/bb/cc/dd/ee<nowiki>| 1 | 25 }} | 1 | 2}}</nowiki></tt> → '''{{#titleparts: {{#titleparts: a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/aa/bb/cc/dd/ee | 1 | 25 }} | 1 | 2}}'''

{{warning}}
You can use #titleparts as a small "string parser & converter", but consider that it returns the first substring capitalized. If lower case is needed, use lc: function to control output.

:<tt><nowiki>{{#titleparts:</nowiki> <span style="color:blue;">one</span>/two/three/four<nowiki>|1|1 }}</nowiki></tt> → '''{{#titleparts:one/two/three/four|1|1 }}'''
:<tt><nowiki>{{#titleparts:</nowiki> one/<span style="color:blue;">two</span>/three/four<nowiki>|1|2 }}</nowiki></tt> → '''{{#titleparts:one/two/three/four|1|2 }}'''
:<tt><nowiki>{{lc: {{#titleparts:</nowiki> <span style="color:blue;">one</span>/two/three/four<nowiki>|1|1 }} }}</nowiki></tt> → '''{{lc: {{#titleparts:one/two/three/four|1|1 }}}}'''

{{warning}}
This function does not degrade gracefully if your input exceeds 255 characters. If the inputted string is 256 characters long or more, this function will simply toss the string back at you.

==General points==
===Substitution===
Parser functions can be [[w:Help:Substitution|substituted]] by prefixing the hash character with <tt>'''subst:'''</tt>:

:<tt><nowiki>{{subst:#ifexist:</nowiki> {{FULLPAGENAME}} <nowiki>| [[</nowiki>{{FULLPAGENAME}}<nowiki>]] | </nowiki>{{FULLPAGENAME}}<nowiki> }}</nowiki></tt> → the code '''<tt><nowiki>[[</nowiki>{{FULLPAGENAME}}<nowiki>]]</nowiki></tt>''' will be inserted in the wikitext since the page {{FULLPAGENAME}} exists.  

{{warning|The results of substituted parser functions are undefined if the expressions contain ''un''substituted volatile code such as [[Help:Magic words#Variables|variables]] or other parser functions. For consistent results, all the volatile code in the expression to be evaluated must be substituted. See [[w:Help:Substitution|Help:Substitution]].}}

===Tables ===
Currently wiki pipe table syntax doesn't work inside conditionals, but this can be worked around by using [[Template:pipe|<nowiki>{{pipe}}</nowiki>]] to replace using '''|''' for the table syntax.

''Parser functions will mangle [[Help:Tables|wikitable]] syntax, treating all the raw pipe characters as parameter divisors.  To avoid this, most wikis create the template [[{{ns:10}}:!]] with its contents only a raw pipe character (<code><nowiki>|</nowiki></code>). This 'hides' the pipe from the MediaWiki parser, ensuring that it is not considered until after all the templates and variables on a page have been expanded. Alternatively, raw HTML table syntax can be used, although this is less intuitive and more error-prone.''

===Stripping whitespace===

Whitespace, including newlines, tabs, and spaces, is stripped from the beginning and end of all the parameters of these parser functions. If this is not desirable, comparison of strings can be done after putting them in quotation marks.

<pre>{{#ifeq: foo            |            foo | equal | not equal }}</pre>
:→ '''{{#ifeq: foo            |            foo | equal | not equal }}'''
<pre>{{#ifeq: "foo           " | "           foo" | equal | not equal }}</pre>
:→ '''{{#ifeq: "foo           " | "           foo" | equal | not equal }}'''

For preventing trimming then- and else-parts, see [[m:Template:If]].

==See also==
* [[Help:Parser functions in templates]]
* [[meta:Help:Calculation]] (to be moved here)
* {{Mediawiki|meta:Help:Newlines and spaces|Help:Newlines and spaces}}
* {{Mediawiki|meta:Help:Comparison between ParserFunctions syntax and TeX syntax|Help:Comparison between ParserFunctions syntax and TeX syntax}}
* {{Mediawiki|Help:Magic words}}
* [[Extension:StringFunctions]]