const keyword usage in Javascript

Question

I was reading the source for a MeteorJS package (this one) when I came across this:

const {
  getMeteorData,
  pure = true,
} = expandedOptions;

I did some research to figure out what this code would do, but couldn't find any other instance of const being used like this, or any documentation to clarify it for me.

Any hints, please?

It's more [destructuring](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment) than `const`. — Ry-, Sep 11 '16 at 02:24

score 1 · Accepted Answer · answered Sep 11 '16 at 02:25

1

It is using es6 to unpack (or destructure) the values inside the expandedOptions object.

const val = {a:1, b:"hello"};
const {
    a,
    b
} = val;

console.log(a); //1
console.log(b); //"hello"

answered Sep 11 '16 at 02:25

gnicholas

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Thanks! I wouldn't have found it by myself (I'lll accept the answer as soon as the SO let me do it) – Daniel Bastos Sep 11 '16 at 02:29

const keyword usage in Javascript

1 Answers1