Why a protected variable of parent class come empty?

Question

I got a protected variable in Father class, the content of this variable will change in Father class but I need to use this variable in sub classes, i.

Answer 1

This is because you're overriding the constructor function. You must call the parent's constructor as well. More info

class Child extends Father {
    function __construct() {
        parent::__construct();

        echo $this->body;
    }
}