I know this is probably a silly question but what does this piece of code do?

PHP Code:

    // Make theme available for translation
    // Translations can be filed in the /languages/ directory
    load_theme_textdomain( 'twentyten', TEMPLATEPATH . '/languages' );

    $locale = get_locale();
    $locale_file = TEMPLATEPATH . "/languages/$locale.php";
    if ( is_readable( $locale_file ) )
        require_once( $locale_file ); 


Im espeically looking at the if statement and what happens if its false or true?

is_readable

yeah i know that but what does the if execute if its true or false?

If its false it doesn't do anything. If its true it executes the line:

PHP Code:

require_once( $locale_file ); 


Basically its checking if the file $locale_file is readable and including it if it is.

ah cheers i wasn't sure how much it executed etc. Cheers!

just like any other IF statement

IF true [do something]

Yeah but it wasn't in { }.

You only NEED to use brackets if the body of an if statement is more than one line:

PHP Code:

if($condition)
     $foo = 'bar';
else
     $abc = '123';