Implementing a two-way queue with PHP

classDEQueue {//Storage    protected $_storage=Array(); //into the head     Public functionUnshift$element)    {        return Array_unshift($this->_storage,$element); }        //into the tail     Public functionPush$element)    {        return Array_push($this->_storage,$element); }        //out of the tail     Public functionpop () {return Array_pop($this-_storage); }        // Head     Public functionshift () {return Array_shift($this-_storage); }        //length     Public functionLength () {return Count($this-_storage); }}

Implementing a two-way queue with PHP