What is the difference between let and var?

You can list out the differences in a tabular format

var

• It is been available from the beginning of JavaScript

• Variables will be hoisted

• It has a function scope

let

• Introduced as part of ES6

• It has a block scope

• Hoisted but not initialized

Let's take an example to see the difference,

function userDetails(username) {

if(username) {

console.log(salary); // undefined(due to hoisting)

console.log(age); // error: age is not defined

let age = 30;

var salary = 10000;

}

console.log(salary); //10000 (accessible to due function scope)

console.log(age); //error: age is not defined(due to block scope)}