The Eduladder is a community of students, teachers, and programmers just interested to make you pass any exams. So we help you to solve your academic and programming questions fast.
In eduladder you can Ask,Answer,Listen,Earn and Download Questions and Question papers.
Watch related videos of your favorite subject.
Connect with students from different parts of the world.
Apply or Post Jobs, Courses ,Internships and Volunteering opportunity. For FREE
See Our team
Wondering how we keep quality?
Got unsolved questions? Ask Questions

JavaScript-Tutorial-for-freshers-in-2021-->View question

Explain the differences between let var and const with the help of -javascript.

Explain the differences between let var and const with the help of -javascript.
And explain the same with the code samples and explain with appropriate examples.

Asked On2021-09-27 03:57:32 by:sharma

Taged users:

Be first to like this question

Be first to dislike this question
Talk about this  Like  Dislike
View all qusetions
The var will allows you to redeclare and update.
 The let and const wont allow you to redeclare. but allows to update.
 For example consider the following lines of code.
In the case of var.
var x = 5; console.log(x); var x =7; console.log(x); x =8; console.log(x);
Out Put will be
In the case of let 
let y = 5; console.log(y); let y =7; console.log(y);
Out put will be
Uncaught SyntaxError: Identifier 'y' has already been declared
But this will work
let y = 5; console.log(y);  y =8; console.log(y);
Out Put will be
In the case of const which cannot be redeclared or updated.
//This will give error
const z = 5; console.log(z);  const z = 6; console.log(z); z =8; console.log(z);
//Same goes here
const z = 5; console.log(z); z =8; console.log(z);
//Only this will work
const z = 5; console.log(z);
Scope of these variables.
var is function scoped where let and const is block scoped. Consider following lines of code.
            var x=12;
                var x2 = 6;
                let y =5;
                const z =6;
The Out Put Will Be.
error ReferenceError: y is not defined
Which means that x2 is even available outside of the braces
var variable will be allocated even before it is assigned. Other hand. Hoisting is JavaScript's default behavior of moving declarations to the top. Consider the following lines of code. 
var  z= 5;
//This will give undefined
Where as let and const gives.
Uncaught ReferenceError: z is not defined

Answerd on:2021-09-29 Answerd By:batsam22

Be first to like this answer

Be first to dislike this answer
Talk about this  Like  Dislike

You might like this video:Watch more here

Watch more videos from this user Here

Learn how to upload a video over here

Lets together make the web is a better place

We made eduladder by keeping the ideology of building a supermarket of all the educational material available under one roof. We are doing it with the help of individual contributors like you, interns and employees. So the resources you are looking for can be easily available and accessible also with the freedom of remix reuse and reshare our content under the terms of creative commons license with attribution required close.

You can also contribute to our vision of "Helping student to pass any exams" with these.
Answer a question: You can answer the questions not yet answered in eduladder.How to answer a question
Career: Work or do your internship with us.Work with us
Create a video: You can teach anything and everything each video should be less than five minutes should cover the idea less than five min.How to upload a video on eduladder