Javascript ES2015 : Instanciate a class and use variables from class

Question

I have a class B which implements another class A.

In the class A I need to use variables defined in class B

class  classA {
    methodA() {
        console.log(parentClass.variableToRetrieve);
    }
}


class classB {
    constructor() {
        this.variableToRetrieve = 1;
        this.A = new classA();
    }
}

var B = new classB();
B.A.methodA();

Whats should I use in classA.methodA ans see 1 in the console ?

Edit

I already thougth to pass the B object in the classA constructor, or pass values, but as I can have hundreds variables and (potentially) millions classA, it will overload the server quickly

classB doesn't implement classA it just has a variable that is an instance of classA. — Titus
– Titus, Commented Mar 11, 2018 at 8:12
As I have a lot of variables, it's not a good idea. I have a hundred parameters and I can have millions of class A :( — Lolo
– Lolo, Commented Mar 11, 2018 at 8:44

atiq1589 · Accepted Answer · 2018-03-11 09:01:32Z

1

You should extend classB with classA

class  classA {

    methodA() {
        console.log('parentClass.variableToRetrieve');
    }

}

class classB extends classA {
    constructor() {
        super()
        this.variableToRetrieve = 1;
    }

    method() {
        this.A = new classA();
    }

}
var B = new classB();
B.methodA();

Updated: I think binding the classB will solve will problem.

class  classA {
    methodA() {
        console.log(this.variableToRetrieve);
    }
}


class classB {
    constructor() {
        this.variableToRetrieve = 4;
    }
}

var B = new classB();
var A = new classA();
A.methodA.bind(B)();

edited Mar 11, 2018 at 9:01

answered Mar 11, 2018 at 8:13

atiq1589

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4 Comments

Lolo Over a year ago

The problem is I can't extend the class, because the main class is a container for class B objects. which can be images, particles, primitives, geopositions,... And in the class B I have some informations like positions, colors, ...

atiq1589 Over a year ago

Sorry did not understand the point why you can't extend the classA. I think classB and classA are related. where classA is the base class and classB will extend classA and add few more information.

Lolo Over a year ago

Imagine class B is the world and class A is a car. A car can't herits from the word but in my car object I need to know some world's values

Lolo Over a year ago

Yes the class binding seems to be the best solution

Shiva Sai · Accepted Answer · 2018-03-11 08:13:30Z

0

Your class A must extend class class B to do that

answered Mar 11, 2018 at 8:13

Shiva Sai

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