class DuiLie

<?php
class DuiLie {
    private $array = array();//声明空数组

    public function setFirst($item){
        return array_unshift($this->array,$item);//头入列
    }

    public function delFirst(){
        return array_shift($this->array);//头出列
    }
     
    public function setLast($item){
        return array_push($this->array,$item);//尾入列
    }

    public function delLast(){
        return array_pop($this->array);//尾出列
    }
     
    public function show(){
        var_dump($this->array);//打印数组
    }

    public function Del(){
        unset($this->array);//清空数组
    }

}

$duiLie=new DuiLie;
$duiLie->setFirst('a');
$duiLie->setFirst('b');
$duiLie->setFirst('c');
$duiLie->setLast('1');
$duiLie->setLast('2');
$duiLie->setLast('3');
$duiLie->show();
$duiLie->delFirst();
$duiLie->show();
$duiLie->delLast();
$duiLie->show();

/*
array (size=6)
  0 => string 'c' (length=1)
  1 => string 'b' (length=1)
  2 => string 'a' (length=1)
  3 => string '1' (length=1)
  4 => string '2' (length=1)
  5 => string '3' (length=1)
array (size=5)
  0 => string 'b' (length=1)
  1 => string 'a' (length=1)
  2 => string '1' (length=1)
  3 => string '2' (length=1)
  4 => string '3' (length=1)
array (size=4)
  0 => string 'b' (length=1)
  1 => string 'a' (length=1)
  2 => string '1' (length=1)
  3 => string '2' (length=1)
*/
?>