php static::和self::的区别

static：访问当前类的static方法

class A {
    public static function who() {
        echo A::class . "\n";
    }
    public static function test() {
        <span style="color: #ff0000;">static::who();</span>
    }
}
class B extends A {
    public static function who() {
        echo B::class . "\n";
    }
}

A::test();//A

B::test();//B

self: 是类内指针，不管是否继承，都访问的是本类的static方法，属性

class A {
    public static function who() {
        echo A::class . "\n";
    }
    public static function test() {
        <span style="color: #ff0000;">self::who();</span>
    }
}
class B extends A {
    public static function who() {
        echo B::class . "\n";
    }
}

A::test();//A

B::test();//A