Retrieve human readable unique object Ids

get_obj_id.php

<?php

/**
 * @param Object $obj The Object to create an Id for
 * @return String A human readable unique ID for the Object
 * 
 * @internal Requires PHP5.2.0 
 * @see http://php.net/manual/en/function.spl-object-hash.php
 */
function get_obj_id($obj)
{

    static $hashes = array();

    $class = get_class($obj);

    $hashes[$class] = isset($hashes[$class]) ? $hashes[$class] : array(null);

    $hash = spl_object_hash($obj);

    if (!($key = array_search($hash, $hashes[$class]))) {
        $hashes[$class][] = $hash;
        $key = array_search($hash, $hashes[$class]);
    }

    return $class . '_' . $key;
}

// Example
// ----------------------
$obj = new StdClass;

$id = get_obj_id($obj);
echo $id; // stdClass_1 

$obj = new StdClass;

$id = get_obj_id($obj);
echo $id; // stdClass_2