温故而知新

<?php
/**
 * User: szliugx@gmail.com
 * Date: 2016/11/4
 * Time: 21:53
 */
 
class Atest
{
    public static $testnum = 0;
    /**
    A方法    
    */
    public function Afun()
    {
        self::$testnum += 2;
        echo self::$testnum."<br/>";
    }
}

class Btest extends Atest
{
    public static $testnum = 0;
    /**
    B方法    
    */
    public function Bfun()
    {
        echo parent::$testnum."<br/>";
        echo self::$testnum."<br/>";
    }

}

$atest = new Atest();
$atest->Afun();
$atest = new Atest();
$atest->Afun();
$btest = new Btest();
$btest->Bfun();

2

4

4

0