- array_map: documentation ( source)
- print_r: documentation ( source)
- array_merge: documentation ( source)
<?php
$def = array('a'=>1, 'b'=>2);
////////
$arr_lang = array('de' => array('a'=>3, 'c'=>4));
$arr_lang = array_map(function ($l) {
return array_merge($def, $l);
}, $arr_lang);
//////
print_r($arr_lang);