从多重类继承（PHP）访问静态var

Question

How can I access $var from C class, i try with parent::parent::$var but this didn't work.

<?php 
class A {
    protected static $var = null;
    public function __construct(){
        self::$var = "Hello";
    }  
}

class B extends A {
    parent::__construct();
    //without using an intermediate var. e.g: $this->var1 = parent::$var; 
}

class C extends B {
    //need to access $var from here.
}

?>

Answer 1

由于变量是静态的，因此您可以像下面那样访问变量-

A::$var;

Answer 2

As long as the property isn't declared as private, then you can just use self:: . Anything other than private properties are available from anywhere in the hierarchy.

class A {
    protected static $var = null;
    public function __construct(){
        self::$var = "Hello";
    }
}

class B extends A {
}

class C extends B {
    function get() { echo self::$var; }
}

(new C)->get();

Hello

See https://eval.in/1022037