1

2

3

4

5

6

7

8

9

class Foo {

    constructor(goal) {

        this.goal = goal;

        Foo.prototype.objectcount++;

    }

}

Foo.prototype.objectcount = 0;

1

2

3

4

5

6

7

8

let f1 = new Foo(78);

console.log(f1.objectcount); // 1

let f2 = new Foo(45);

console.log(f2.objectcount)// 2

let f3 = new Foo(45);

console.log(f3.objectcount)// 2

console.log(f1.objectcount === f2.objectcount);

console.log(f2.objectcount === f3.objectcount);// true