php实现后期静态绑定(2)-木庄网络博客

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<?phpclass A {
    private function foo() {
        echo "success!\n";
    }    public function test() {
        $this->foo();        static::foo();
    }
}class B extends A {
   /* foo() will be copied to B, hence its scope will still be A and
    * the call be successful */}class C extends A {
    private function foo() {
        /* original method is replaced; the scope of the new one is C */
    }
}$b = new B();$b->test();$c = new C();$c->test();   //fails

结果：

success!
success!
success!
Fatal error:  Call to private method C::foo() from context 'A' in /tmp/test.php on line 9

转发和非转发调用

后期静态绑定的解析会一直到取得一个完全解析了的静态调用信息为止。另一方面，如果静态调用使用 parent:: 或者 self:: 将转发调用信息。

例：

class A {
    public static function foo() {
        static::who();
    }    public static function who() {
        echo __CLASS__."\n";
    }
}class B extends A {
    public static function test() {
        A::foo();        parent::foo();        self::foo();
    }    public static function who() {
        echo __CLASS__."\n";
    }
}class C extends B {
    public static function who() {
        echo __CLASS__."\n";
    }
}
 
C::test();