What is the difference between self and "ClassName"?

Question

PHP

class A {
    public static $var = 1;
    public function hello() {
        echo self::$var;
        echo A::$var;
    }
}

How will self::$var and A::$var differ here?

Answer 1

A::$var
call in the context of class A
call in the context of a class in which there is definitely (in this case class A)
a call in the context of the current class,
i.e. in the case of inheritance:
- if you have a class B that is inherited from class A and in which $ will be redefined var, it will be used,
- in the case of self, the variable will be used from where self is called
, i.e. nothing in your particular case, but it is better to use static