This is a very simple but useful function that returns the first variable from a given list of variables that has a value.


$one = 1; $two = array("", null, 4); $three= array();

print_r(either($three,$two, $one));

function either($arr) {

        if(!(func_num_args() == 1 && is_array($arr)))
            $arr = func_get_args();
    
        foreach($arr as $v) {
                if(is_array($v)) {
                        if(count($v) != 0) return either($v);     
                }else if($v) {
                    return $v;
                }
        }
}


An example where this could be used is $_POST/$_GET variables - if the $_POST variable is not available the alternative could be to use a $_GET variable, failing that a default value could be applied, e.g.

$query = either($_POST[query], $_GET[query], "test")