<?php

/* A Function created by myself for checking multiple array keys
For Example u got an Array like $_SESSION and u wanna know if the keys 'user','pass','email' and 'type' exists.

*/

function mKeyChecker($arr,$keys=array()) {
    if(count($keys) > 1) {
        $valid_keys = 0;
        foreach($keys as $key) {
            if(array_key_exists($key,$arr)) $valid_keys++;
        }
        if($valid_keys == count($keys)) {
            return true;
        } else {
            return false;
        }
    } else if(count($keys) == 1) {
        if(array_key_exists($key[0],$arr)) {
            return true;
        } else {
            return false;
        }
    } else {
        return false;
    }
}

// Execution Example

if(mKeyChecker($_SESSION,array('id','user','email','type'))) {
    echo "is!";
} else {
    echo "not!";    
}

?>