JavaScript Explanation of brackets

Question

Can someone explain me which bracket here is used for what?

let myModule = (function() {})();

i know that the inner part = function() { // Some stuff here } is a function, so what does

(innerpart)();

? How and why is it different from

let myModule = function() {}

Google IIFE. That's what we call it – Jonathan May 21 '19 at 11:34 — Jonathan, May 21 '19 at 11:34
https://developer.mozilla.org/en-US/docs/Glossary/IIFE – Roberto Zvjerković May 21 '19 at 11:36 — Roberto Zvjerković, May 21 '19 at 11:36
(innerpart)(); is used for self invokable function. – Sunny Goel May 21 '19 at 11:36 — Sunny Goel, May 21 '19 at 11:36
Wow Thank you very much, that was fast – MasterOfDesaster May 21 '19 at 11:36 — MasterOfDesaster, May 21 '19 at 11:36

Lucas Dolsan · Accepted Answer · 2019-05-21T11:43:22.087

2

when you declare do:

let foo = function () {}

you're just declaring a function foo

when you do:

let foo = (function() {})();

edited: thanks to @VLAZ

you're declaring a function foo and calling it right away. It's the same as:

let f = function() {} 
let foo = f()

edited May 21 '19 at 11:43

answered May 21 '19 at 11:35

Lucas Dolsan

That last part is not quite correct. That must be `foo = foo()` to be equivalent. – deceze May 21 '19 at 11:37
It's not. `foo` will be a completely different thing in those two cases. – Roberto Zvjerković May 21 '19 at 11:37
1

More like `f = function() {}` followed by `foo = f()` because you are getting the result of that execution. Also, you are throwing away `f` afterwards. – VLAZ May 21 '19 at 11:37

1 Answers1