- preg_replace_callback: documentation ( source)
<?php
$asdf = array("temp_derp" => "15", "temp_derpier" => "30", "temp_youdick"=>"50");
echo preg_replace_callback("/temp_[a-z0-9_]*/i", function($match) {return $GLOBALS["asdf"][$match];},"temp_derp+temp_derpier+temp_youdick");