Comments on: What on Earth does a double underscore then parenthesis mean in PHP? __()

By: Eat My Business » Blog Archive » What on Earth does a single underscore then parenthesis mean in PHP? __()

Sun, 22 Jul 2007 19:22:50 +0000

[…] Further to my previous post on the double underscore __() … […]

By: Jeremy

Jeremy — Sat, 14 Mar 2009 12:24:46 +0000

Thank you! As someone who writes plugins and hacks the code for wordpress (from time to time as needed), it can be really hard to find someone who knows the answers to tough Wordpress questions (there are less advanced coder types than not after all).

Your post saved me a bunch of searching, thanks!

By: truetone

truetone — Wed, 17 Jun 2009 19:50:29 +0000

The CakePHP framework uses it too. Initially, I’d thought it was a sort of shortcut for echo or print, but interestingly enough, it’s a lot more. Thanks for the explanation.

By: Eduardo Baldan

Eduardo Baldan — Tue, 22 Sep 2009 23:01:29 +0000

Thanks mate! I was trying to figure out what the @@&%* was those underscores.
I think it should be better explained on codex.

[]’s!

By: jeff

jeff — Tue, 03 Nov 2009 02:54:58 +0000

thanks - i couldn’t figure out what the double underscore was doing

By: darky

darky — Sat, 07 Nov 2009 16:52:27 +0000

I was weired, when I saw this in wordpress, too.
But searching in google only for “php __”, the first results gave me the answer.
But just your blog gave me the answer that is is user-defined^^
Thx!

By: César Salazar

César Salazar — Sun, 22 Nov 2009 05:08:08 +0000

Thanks! I’ve always wondered what’s with the double underscore.

By: Anca

Anca — Thu, 07 Jan 2010 00:26:05 +0000

Wow, thank so much for this post. You’ve saved me a lot of searching.

By: Emmanuel

Emmanuel — Sun, 07 Feb 2010 10:07:27 +0000

Thanks too, I was contracted to write my first wordpress widget and those __(something) was really bugging me because I kept wondering if there was some obscure PHP language construct I’ve been missing for years.

By: timemachine

timemachine — Mon, 19 Apr 2010 03:42:37 +0000

not sure if this is relevant after all this time but FYI ..

from the website :
http://webdevelopmenttutorials.com/phpvariablestutorial.php

Magic Constants
Magic constants, as they are called, are not acutally constants but effectively behave like constants and are pre-defined. Magic constants use the same naming convention as PHP constants.

The full list of magic constants can be found here.

There are 7 magic constants that change depending on where they are used. They are listed below.

name description
__LINE__ The current line number of the file.
__FILE__ The full path and filename of the file. If used inside an include, the name of the included file is returned. Since PHP 4.0.2, __FILE__ always contains an absolute path with symlinks resolved whereas in older versions it contained relative path under some circumstances.
__DIR__ The directory of the file. If used inside an include, the directory of the included file is returned. This is equivalent to dirname(__FILE__). This directory name does not have a trailing slash unless it is the root directory. (Added in PHP 5.3.0.)
__FUNCTION__ The function name. (Added in PHP 4.3.0) As of PHP 5 this constant returns the function name as it was declared (case-sensitive). In PHP 4 its value is always lowercased.
__CLASS__ The class name. (Added in PHP 4.3.0) As of PHP 5 this constant returns the class name as it was declared (case-sensitive). In PHP 4 its value is always lowercased.
__METHOD__ The class method name. (Added in PHP 5.0.0) The method name is returned as it was declared (case-sensitive).
__NAMESPACE__ The name of the current namespace (case-sensitive). This constant is defined in compile-time (Added in PHP 5.3.0).

By: Josh

Josh — Fri, 23 Apr 2010 14:17:25 +0000

If you’re looking for syntax information about the use of the __() function in WordPress, you can find it here:

http://codex.wordpress.org/Function_Reference/_2

By: Steve

Steve — Wed, 25 Aug 2010 10:03:26 +0000

Doh! I actually read this in the Wordpress bible, and then forgot! Thanks to your post I re-discovered the answer. Nice bit of digging :-)

By: Chris Heney

Chris Heney — Mon, 06 Sep 2010 14:05:24 +0000

I was able to get lucky with googling for: wordpress double underscore and your site came up… I have always wondered that myself.

When making your own plugins you may also use the built in function called load_plugin_textdomain($path_to_lang_files);

The language files can be .mo / .po / .pot files.

By: Leslie

Leslie — Wed, 06 Oct 2010 19:36:52 +0000

Brilliant! Thanks for taking the time to post this, it came up at the top of a Google search for
php __

Super info, much appreciated.

By: Andrei

Andrei — Wed, 11 May 2011 09:08:24 +0000

Informative, even after all these years. Thanks!

By: tommat

tommat — Tue, 07 Jun 2011 19:14:29 +0000

Thanks ! Now It’s clear :)

By: Steve

Steve — Wed, 20 Jul 2011 21:08:16 +0000

Reporting in that Sensio Labs’ Symfony framework also uses this convention for localized strings. Nice to see there is quite a bit of standardization here with the big players.

By: dest

dest — Wed, 19 Oct 2011 16:28:46 +0000

The function is defined in the wp-includes/l10n.php file