Javascript - Destructuring Using the rest Syntax

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Introduction

The following code shows how to use destructing pattern and rest syntax. 

var num1, num2, rest; 
var x, y, z; 

[num1, num2, ...rest] = [1, 2, 3, 4, 5]; 
[x, y, z] = [1, 2, 3, 4, 5]; 

console.log(num1);        // 1 
console.log(num2);        // 2 
console.log(rest);        // [3, 4, 5] 
console.log(x, y, z)      // 1 2 3

Here, using destructuring we assign values to the variables num1, num2, and rest.

A SyntaxError will be thrown if a trailing comma is used on the left-hand side with a rest element. 

var [a, b,] = [1, 2, 3]; 
console.log(a, b)               // 1 2 
var [num1, ...num2,] = [1, 2, 3]; 
// SyntaxError: rest element may not have a trailing comma

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