what is the explanation of this kind of instruction let {max}=Math;

Question

I came accross this line of javascript code

let {max}=Math;

that allows you to do this:

let a=max(1,2) //2

Without using the Math object like this:

Math.max(1,2)

I don't know where to find the documentation of this syntax because all I have is that line of code and not a single clue to help me search on google so anyone knows about this practice ?

same as `let max=Math.max`, which works fine because the max method doesn't use a specific _this_ binding. — dandavis, Apr 16 '20 at 19:55

score 4 · Accepted Answer · answered Apr 16 '20 at 19:36

4

This is called Destructuring Assignment and you can find documentation here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment

answered Apr 16 '20 at 19:36

Garrett Motzner

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LetItBeAndre · Answer 2 · 2020-04-16T19:55:34.313

What you see there is called Destructuring assignment. You'll find plety of examples when you Google for Destructuring assignment JS ;)

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment

Anyway, in this particular case you assign the property max (a function in this case) from Class Math. This allows you to just call max directly.

Imagine having an object DestructTest with a property x Then you can get the property x by just typing const {x} = DestructTest Instead of const propX = DestructTest.x JavaScript takes care for you to get the wanted property for you if you just ask for the right name ;) Hope this makes things a bit more clear. Cheers

what is the explanation of this kind of instruction let {max}=Math;

2 Answers2