Double underscore in PHP?

Question

What do double underscores mean in these lines of PHP code?

$WPLD_Trans['Yes']=__('Yes',$WPLD_Domain); $WPLD_Trans['No']=__('No',$WPLD_Domain); 

Answer 1

It looks like you are using Wordpress - wp-includes/l10n.php defines __ as a function that translates a string (similar to gettext and its alias _ , but with an optional parameter for specifying the domain explicitly).

Answer 2

Strictly speaking, this does not mean anything in PHP, since it is not a predefined function. However, in many environments, such as CakePHP and other libraries, double underlining is a function used to translate strings based on a user language / language preference.

Answer 3

As already mentioned, it is usually used to translate text between languages, but in fact it is used in the same context as any function call.

 testfunction(); 

no different from

 __(); 

Answer 4

WordPress documents its __ () function, part of the localization technology here: https://make.wordpress.org/polyglots/handbook/translating/working-with-core/#localization-technology

It’s hard to find documentation because __ (), __ ('') or __ ("") are not very searchable, double underscores and parentheses (parentheses) are keywords to use.

Answer 5

A similar or third-party GNU gettext implementation :

http://www.php.net/manual/en/function.gettext.php

Note. You can use the underscore character '_' as an alias for this function.