Template talk:Ifndef

Usage

{{Ifndef|value|result}} yields result  if value  is blank.

This simple template cannot be substituted, it's used to simplify the following equivalent but somewhat cryptic (names don't matter) code variants:

{{{2{{{1|}}}|}}}

{{{result{{{value|}}}|}}}

{{{then{{{test|}}}|}}}

Example

Code	Result
1 {{Ifndef| |empty}}	1 empty
2 {{Ifndef|x|gotcha}}	2
3 {{Ifndef| {{{1| }}} | {{{1| }}} undefined}}	3 undefined
4 {{Ifndef| {{{1  }}} | {{{1  }}} bad idea}}	4
5 {{Ifndef| {{ns:0}} | main namespace}}	5 main namespace

Unlike ifdef the minimalistic ifndef cannot reject a missing second parameter.

For more info see: meta.wikimedia.org Ifndef