rewrite_static

<?php 
class MyObject {
    
    public static $myStaticVar = 0;
    
    function myMethod() {
        self::$myStaticVar += 2; 
        echo self::$myStaticVar."
";
    }
}

class MyOtherObject extends MyObject {
    
    public static $myStaticVar = 0; //重写了myStaticVar
    
    function myOtherMethod() {
        
        echo parent::$myStaticVar."
";
        echo self::$myStaticVar."
";
    }
}
$instance1 = new MyObject();
$instance1->myMethod();
$instance2 = new MyObject();
$instance2->myMethod();
$instance3 = new MyOtherObject();
$instance3->myOtherMethod();
//2
//4
//4
//0