Javascript let vs var

Javascript Let vs Var

Into this post we are going to discuss difference between Javascript var and Let.

we are going to discuss about Javascipt variable declaration method like where user can declare variable with var and where user can declare variable with let.

Global Variable Declaration:

If we define var and let variable same globally then let variable will not get added into global window object while var variable will get added to global window object.

So let's declare two variables at the time of window loaded

let Visionfortech_let = "Visionfortech is defined as let variable"

var Visionfortech_var = "Visionfortech is defined as var variable"

console.log(Visionfortech_let);
o/p : undefined

console.log(Visionfortech_var);
o/p : Visionfortech is defined as var variable
  

Redeclare Variable:

So Here let's discuss about one more example of let vs var into Javascript.You can not declare let variable but you can redeclare var variable

'use strict';

var let_vs_var = "Javascript let vs var";

var let_vs_var = "Difference Between let and var Javascript"; 
//replaced easily



'use strict';

let let_vs_var = "Javascript let vs var";

let let_vs_var = "Difference Between let and var Javascript"; 
// Error: let_vs_var is already declared

Javascript Let Example : 

let vision = 1;

if (vision === 1) {
  let vision = 2;

  console.log(vision);
  // output: 2
}

console.log(vision);
// output: 1
  

Now let see the scope example of Javascript let vs var.

var let_vs_var = 1;

var javascript_var = 2;

            

if (a === 1) {

     var let_vs_var = 11; // the scope is global

     let javascript_var = 22; // the scope is inside the if-block

            

     console.log(let_vs_var);  // 11

     console.log(javascript_var);  // 22

}          

console.log(let_vs_var); // 11

console.log(javascript_var); // 2  

Enjoy....!!!!

Feel free to comment below your experience with above approach and If you still find any problem  with above steps Let me know I would love to help you to resolve your  problem.

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