Using the Rest Operator with Function Parameters

Tell us what’s happening:

Hello guys, Please help with this. Am not getting it

Your code so far

const sum = (function() {
  "use strict";
  return function sum(...args) {
    const args = [ x, y, z ];
    return args.reduce((a, b) => a + b, 0);
console.log(sum(1, 2, 3)); // 6

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Link to the challenge:

What do the failing tests say?

TypeError: unknown: Duplicate declaration “args”

args is declared when you write sum(...args)
Then when you write const args = [ x, y, z ]; you are attempting to redeclare something that already exists.

args is defined within the parameters , so you would not want to redefine args again. Instead, you want to declare 3 variables (x, y, and z) by destructuring args.

Ok, but then where does the rest operator come in



The three dots before args.

That is exactly what i did, …args

Yes, but now you don’t need the extra line defining args.

Sorry for the confusion in my earlier reply about needing to destructure args. I only half read the instructions.

Ok, now i understand. Thought i wasnt supposed to touch their own code. Thanks a lot, you have been really helpful