Question

What is the difference between let and var in Javascripts?

Answer 1

You can list out the differences in a tabular format

var	let
It is been available from the beginning of JavaScript	Introduced as part of ES6
It has function scope	It has block scope
Variables will be hoisted	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); // ReferenceError: Cannot access 'age' before initialization
    let age = 30;
    var salary = 10000;
  }
  console.log(salary); //10000 (accessible due to function scope)
  console.log(age); //error: age is not defined(due to block scope)
}
userDetails("John");