Skip to main content Accessibility Feedback

Rest parameters in JavaScript functions

On Friday, we looked at the arguments object in JavaScript functions. Today, we’re going to look at rest parameters.

Rest parameters work a lot like the arguments object, but with two notable advantages.

  1. You can give them to any name you’d like.
  2. You can start at any parameter you want.

You define rest parameters by creating a parameter prefixed with .... Any arguments provided at or beyond the rest parameter on a function get combined into an array that’s assigned to the rest parameter’s name.

In the example below, ...moreArgs is a rest parameter.

function logStuff (arg1, arg2, ...moreArgs) {

	// Logs arg1

	// Logs arg2

	// Logs an array of any other arguments you pass in after arg2


// In this example...
// arg1 = 'chicken'
// arg2 = 'tuna'
// moreArgs = ['chips', 'cookie', 'soda', 'delicious']
logStuff('chicken', 'tuna', 'chips', 'cookie', 'soda', 'delicious');

Unlike the arguments object, rest parameters are traditional arrays that can be used with all of the array methods. Here’s a demo.

Here’s a function you can use to add() two or more numbers together, written with a rest parameter.

function add (...nums) {

	// Set a starting total
	let total = 0;

	// Add each number to the total
	nums.forEach(function (num) {
		total += num;

	// Return to the total
	return total;


One other notable benefit of rest parameters over the arguments object: they work in ES6 arrow functions (the arguments object does not).