spread operator in javascript

Question

In the below code,

function myFunction(x, y, z) { }
var args = [0, 1, 2];
myFunction(...args);

Is spread operator(...) unpacki

Answer 1

... is known as Spread/Rest operator depending upon how and where it is used.

What does spread operator do? The spread operator allows an expression to be expanded in places where multiple elements/variables/arguments are expected.

Before ES6, arguments is an array like object, corresponds to the arguments passed to a function. Here is a quick look at its use:

(function(a, b, c){
   console.log(arguments);
})(1, 2, 3);
Output would be [1,2,3].

In ES6, the same can be written as:

function getSum(x, y, z){
   console.log(x+y+z);
}

can call either of two ways:

getSum(...[10,20,30]);

or

var argArr = [10,20,30];
getSume(...argArr);

We have put ... in front of array, so it spread the elements of array into individual values.