Modiwl:Yesno/doc: Gwahaniaeth rhwng fersiynau

== Syntax ==

 

 

<code>value</code> is the value to be tested. Boolean input or boolean-style input (see below) always evaluates to either <code>true</code> or <code>false</code>, and <code>nil</code> always evaluates to <code>nil</code>. Other values evaluate to <code>default</code>.

First, load the module. Note that it can only be loaded from other Lua modules, not from normal wiki pages. For normal wiki pages you can use {{tl|yesno}} instead.

 

local yesno = require('Module:Yesno')

 

Some input values always return <code>true</code>, and some always return <code>false</code>. <code>nil</code> values always return <code>nil</code>.

 

-- These always return true:

yesno('yes')

-- A nil value always returns nil:

yesno(nil)

 

String values are converted to lower case before they are matched:

 

-- These always return true:

yesno('Yes')

yesno('N')

yesno('fALsE')

 

You can specify a default value if yesno receives input other than that listed above. If you don't supply a default, the module will return <code>nil</code> for these inputs.

 

-- These return nil:

yesno('foo')

yesno(5, 'bar')

yesno(function() return 'This is a function.' end, 'bar')

 

Note that the blank string also functions this way:

yesno('') -- Returns nil.

yesno('', true) -- Returns true.

yesno('', 'bar') -- Returns "bar".

 

Although the blank string usually evaluates to false in wikitext, it evaluates to true in Lua. This module prefers the Lua behaviour over the wikitext behaviour. If treating the blank string as false is important for your module, you will need to remove blank arguments at an earlier stage of processing.