What does using multiple = operators do in Javascript?

Question

For example:

What does

this.head = this.tail = new Node(value)

do? How does javascript interpret this line?

Is this the same as writing:

this.head = new Node(value);
this.tail = new Node(value);

If so, is there any limitation on when and where this one line approach can be used?

`a = b = c` is equal to `a = (b = c)`, see [operator precedence](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence) — ASDFGerte, Sep 21 '21 at 21:05
Does this answer your question? [Multiple left-hand assignment with JavaScript](https://stackoverflow.com/questions/1758576/multiple-left-hand-assignment-with-javascript) — Ervin Szilagyi, Sep 21 '21 at 21:05

score 0 · Answer 1 · answered Sep 21 '21 at 21:06

0

No, it's assigning the same value to both variables. So it's equivalent to

this.tail = new Node(value);
this.head = this.tail;

Your equivalence would create 2 different Node objects, but there's only 1.

answered Sep 21 '21 at 21:06

Barmar

1 Answers1