How do the keywords self:: and static:: differ in the context of calling methods and properties in PHP?

In PHP, the keywords self:: and static:: are used to access methods and properties within a class, but they have different semantics:

• self:: refers to the method or property of the class where the code is written, ignoring inheritance. It is a static call tied to the current class.

• static:: is late static binding. When called from a subclass, static:: refers to the class from which the method was called, taking inheritance into account.

Example:

class A {
    public static function who() {
        echo "Class A\n";
    }
    public static function test() {
        self::who();    // always calls A::who()
        static::who();  // calls the method of the class that called test()
    }
}

class B extends A {
    public static function who() {
        echo "Class B\n";
    }
}

B::test();

The output will be:

Class A
Class B

This shows that self:: is tightly bound to class A, while static:: considers inheritance and calls the method of class B.