Double Underscore in PHP?

Question

What does the double underscores in these lines of PHP code mean?

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


        

Answer 1

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

It is difficult to find documentation because __(), __('') or __("") is not very searchable, double underscore and parentheses (round brackets) are keywords to use.