View source for Template:Void/doc

{{documentation subpage}}
{{sister templates|V=3|wsr=|wqt=|wdy=void|wnw=void}}

This template returns the empty string. 

==Usage==
[[mw:Help:ParserFunctions|Parser functions]] for branching (<code>#if, #ifeq, #ifexpr, #ifexist, #iferror, #switch</code>) trim the result. To be able to specify a result starting and/or ending with newlines and/or spaces, the possible results specified in the call of such a  branching function (then-part, else-part, switch values) are template names, and the parser function call forms the title part inside a pair of double braces. Unnamed parameters in this outer call are not trimmed. If there is a then-part but no else-part, or in the case of #switch without default, the corresponding template name has to return the empty string regardless of any parameters specified in the call. This is achieved by using this template.

The template is used in:
*[[Template:Xpd/w]] - for an if-then construct without else-part; used in all [[Help:Expansion demo templates|expansion demo templates]]
*[[Template:Nrow]] - for optionally returning a newline at the end; used in [[Template:Menu]]

==Alternatives==
It is also possible to use parser function <code><nowiki>{{ns:0}}</nowiki></code> (the empty string for the main [[m:Help:Namespace|namespace]]). However, any parameters of <code><nowiki>{{ns:0}}</nowiki></code> contribute to the [[w:Wikipedia:Template limits|post-expand include size]], while this is not the case with this template.

<nowiki>{{{{#if..:..|a|void}}|b}}</nowiki> is equivalent with 
<nowiki>{{{{#if..:..|a|p2}}|b|}}</nowiki> provided that <nowiki>{{a|b}}</nowiki> is equivalent with 
<nowiki>{{a|b|}}</nowiki>, e.g. because template A does not use a parameter 2, or because it treats empty and undefined the same.

==Examples==
*{{xpdoc|void}}.
*{{xpdop3c|void|p}}.
*<code><nowiki>{{tt|void}}</nowiki></code> using {{timc|Tt}}  gives "{{tt|void}}".

Compare:
*{{xpdoc|ns:0}}.
*{{xpdop3c|ns:0|p}}.
*<code><nowiki>{{tt|ns:0}}</nowiki></code> gives "{{tt|ns:0}}".

==Comments==
The template can be used for adding comments in the wiktext, without affecting the rendering. In the usual way it can be controlled whether on substitution of a template containing a call of void it is substituted (i.e., the comment is removed) or not. See also [[Help:Substitution#Multilevel substitution]] and [[Help:Comment tags#Substitution]].

==See also==
*[[Template:Voidd]]
*[[w:Template:Void]]

<includeonly>[[Category:Miscellaneous templates|{{PAGENAME}}]]</includeonly>