php实现栈

<?php    class stack{        private $_data = array();        private $_end = null;        public function push($data){            if($this->_end === null)                $this->_end = 0;            else                 $this->_end ++;                 $this->_data[$this->_end] =$data;        }                 public function pop(){            if(empty($this->_data))                return false;            $ret = $this ->_data[$this->_end];            array_splice($this->_data,$this->_end);            $this->_end--;            return $ret;            }                     public function getData(){            return $this->_data;        }    }    $stack = new stack();    $stack->push('chuan');    $stack->push('shan');    $stack ->push('jia');    $pop_data = $stack ->pop();    var_dump($pop_data,$stack->getData());

结果： string(3) "jia"array(2) {  [0]=>  string(5) "chuan"  [1]=>  string(4) "shan"}