父子关系和对象查看器中的导航

Question

Is it a problem that when I view a parent-child relationship written in JavaScript you can infinitely navigate through the object?

Take the following as an example

class Parent {
    constructor() {
      this.child = null;
    }
}

class Child {
    constructor() {
      this.parent = null;
    }
}

let p1 = new Parent();
let c1 = new Child();

p1.child = c1;
c1.parent = p1;

When viewing this object in Chrome when navigating the object you can iterate it infinitely, which is obvious why but is it bad practice is there another way to code parent / child relationships in JavaScript?

child -> parent -> child -> parent -> child -> parent -> child -> and so on ...

Answer 1

This is a natural effect of objects being passed by reference, rather than by value.

 const x = { a: 'INITIAL', b: 'INITIAL', } const y = { x, cloneX: { ...x } } console.log(y) xa = 'CHANGED' console.log(y) 

From looking at the question, and your comments, it sounds as though this is unlikely to be particularly new to you.

But what we can tell from knowing that the variable is passed by reference is that what you're seeing in the console is fairly natural once you consider that the parent/child values are just pointers, so naturally you'll be able to keep following them.

This doesn't imply however that there will be any kind of memory issue, as the code isn't keeping an infinite series of copies of objects; each only stores a reference, it just happens in this case to be circular.