What's the difference between object notations?

Question

hey I'm wondering why there are 3 different notations in JavaScript to define a object.

var obj = { attribute : value }
function obj(param){ attribute = param }
var obj = (param) => { attribute = param }

Answer 1

Nguyễn Văn Hoàng
Sorry, I just corrected it, now it's correct

Answer 2

and what is the benefit of 3?

Answer 3

so there is no benefit using 3 over 2 notation?

Answer 4

Yahiko Does the 2nd one with a = really work? I never encountered that kind of syntax before.

Answer 5

It's supposed to be
================
1. obj ={attribute: param}

2. function obj(param){
this.attribute = param
}

3. var obj(param) =>{
this.attribute = param;
}

Answer 6

hans
I rarely use it ,so I don't know

Answer 7

1st defines an object.

2nd and 3rd declare a class. (Where 3rd is syntactic sugar version of 2nd introduced in EM6).

You have to use "new obj(arg)" to actually create an instance of the class.

Answer 8

hans the 2nd and 3rd don't create an object.

The other way to create an object outside literal notation is var obj = new Object().

People still prefer the literal version due to its convenience. It is also recommended by many IDE.

Edit: sorry was mistaking the question. No, there's no technical benefit using 3 over 2.