php实现入栈 出栈

栈原理：先进后出，设置栈的最大容量，容器
++i：如果i=1 那么这个就是先加 变为2在作为下标
i++：如果i=1 那么这个就是2先作为下标使用，在加变3
当然大家也可以根据容器的个数count后进行判断是否存满

<?phpclass Data{const MAXSIZE = 4;// 栈最大容量private $top = 1;private $data = array();// 利用数组存储数据public function __construct(){$this->data = array();}// 入栈public function push($string){if ($this->top >= self::MAXSIZE+1){echo \'data is full...\';return false;}$this->data[++$this->top] = $tring;}// 出栈，返回出栈元素public function pop(){if ($this->top == 1){echo \'data is empty...\';return false;}$string = $this->data[$this->top];unset($this->data[$this->top--]);return $string;}// 遍历栈public function show(){if ($this->top == -1){echo \'data is empty\';return false;}for($i=$this->top; $i>-1; $i--){echo $this->data[$i].\'<br/>\';}}}$data = new Data;$data->push(1);$data->push(2);$data->push(3);$data->push(4);$data->show();$a = $data->pop();$a = $data->pop();$a = $data->pop();$a = $data->pop();$stack->show();```