Javascript Introduction
Comments in Javascript
Javascript Variables
Difference between var, let and const in Javascript
Datatypes
Assignment Operators
Logical Operators
Comparison Operators
Actions alert, prompt & confirm

Javascript Flow Control
Conditional Statements in Javascript
Nullish coalescing operator in Javascript
Break and Continue in Javascript
Loops in javascript
for loop in Javascript
while loop

Javascript Functions
Javascript Functions
JavaScript Arrow Function

Javascript Objects
Javascript Objects

Javascript Array
Javascript Arrays

Javascript Error Handling
Error Handling in Javascript

Javascript ES6
Set
Javascript Spread Operator
Rest Parameter in Javascript

Javascript Asynchronous
Javascript Callback Function
Promises in Javascript
Promise Chaining
Async-Await in Javascript

Javascript DOM
DOM Document
DOM Elements
DOM Attributes
DOM Manipulation
DOM Node Lists
Javascript Events
DOM Traversing Elements
DOM EventListener

Javascript Class
Classes in javascript
Class Inheritance

Javascript Design Principles
SOLID - The Single responsibility principle in javascript
SOLID - Open-Closed principle in Javascript

Other Topics
Javascript Hoisting
Filter, Map and Reduce functions in Javascript
Closure in Javascript
Optional chaining operator in Javascript
Consoling in table format in javascript
Fetch API in Javascript
HTML web Storage API
Checking the online or offline status of the browser

Rest Parameter in Javascript

Like Spread Spread Operator the Rest Parameter shares the same syntax. The three dots ... .The difference is both of them behave different. The spread operator will expand the contents of an iterable. In contrast, the rest parameter collects all the remaining elements into an array.

Example 1

            function addValues(...params) {
    let sum = 0;
    for(let i=0;i<params.length;i++){
        sum += params[i];
    }
    return sum;
}

let sum = addValues(2,3,4,5);
console.log(sum);

        

If we run the program, it will produce the result as 14. In the addValues() function we can pass any number of parameters and get the sum of those supplied parameters. The addValues() function gets all the parameters using rest paramters in 'params' parameter. Now we can call addValues() function with any number of integer parameters to return the result of sum of parameters.

Example 2

            let arrayList = [1, 2, 3];
const [ listOne, ...listTwo ] = arrayList;
console.log(listOne);
console.log(listTwo);

        

If we run the program, it will produce the result as below

1
[2,3]

Example 3

            const userInfo = {
    firstName:'Readers',
    lastName:'Buddy',
    age:2
}

const {age, ...userInfo} = userInfo;
console.log(age);
console.log(userInfo)

        

If we run the program, it will produce the result as below.

22
{firstName: "Readers", lastName: "Buddy", age: 2}

Rest Parameter in Javascript

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