I am making an application using JavaScript. One thing that I noticed is that when I call super() from child class constructor, I cannot use child class fields.

For example:

class Parent {
    constructor() {
        console.log(this.x);
    }
}
class Child extends Parent {
    x = 5;
    constructor() {
        super();
    }
}

Output: undefined

As you see, the parent constructor cannot access the x field of the child constructor. There are similar questions on stackoverflow like:

Access JavaScript class property in parent class

The solution they give is to use an init() method on the Parent class. I realized that every method other than the constructor of the Parent class has access to child fields.

class Parent {
    init() {
        console.log(this.x);
    }
}
class Child extends Parent {
    x = 5;
    constructor() {
        super();
        this.init();
    }
}

Output: 5

However, I can also get access to the x field by using Timeout with delay of 0:

class Parent {
    constructor() {
        setTimout(() => console.log(this.x), 0);
    }
}
class Child extends Parent {
    x = 5;
    constructor() {
        super();
    }
}

Output: 5

All the answers on stackoverflow give the solution, but nobody explains how and why this happens. So my question is:

1. Why the constructor doesn't have access to fields of the child class?

2. Why adding a timeout function gives access to the fields of the child class?