Template:Void/doc

This is a documentation subpage for Template:Void.
It contains usage information, categories, and other content that is not part of the original template page.

Similar templates at English sister projects
	Meta	Void/doc
	Wikipedia	Void/doc
	Commons	Void/doc
	Wikibooks	Void/doc
	Wikinews	void
	Wikispecies	Void/doc
	Wikiversity	Void/doc

This template returns the empty string.

Usage

Parser functions for branching (#if, #ifeq, #ifexpr, #ifexist, #iferror, #switch) 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 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 {{ns:0}} (the empty string for the main namespace). However, any parameters of {{ns:0}} contribute to the post-expand include size, while this is not the case with this template.

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

Examples

"{{void}}" → "" [1].
"{{void|p}}" → "" [2].
{{tto|void}} using Template:Tto containing "{{{{{1}}}|a{{{2}}}b{{{2}}}c{{{2}}}d}}<noinclude>

{{Documentation|content= This 2004 template was once placed at {{tl|tt}}, until it was converted into a [[Template:Languageicon|Languageicon]] template in 2021. Nearly a year later, the history was splitted and it is now here. }} </noinclude>" gives "".

Compare:

"{{ns:0}}" → "" [3].
"{{ns:0|p}}" → "" [4].
{{tto|ns:0}} gives "".

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 mw:Help:Comment tags#Substitution.