JavaScript Let

JavascriptWeb DevelopmentObject Oriented Programming

The JavaScript Let keyword introduced in 2015 allows us to define block scoped variables.

Following is the code for declaring variable using Let keyword in JavaScript −


 Live Demo

<!DOCTYPE html>
<html lang="en">
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
   body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
      font-size: 18px;
      font-weight: 500;
      color: red;
<h1>JavaScript Let</h1>
<div class="sample"></div>
<div style="font-weight: bold; color: black;" class="result"></div>
<button class="Btn">CLICK HERE</button>
Click on the above button to access the varible
   let sampleEle = document.querySelector(".sample");
   document.querySelector(".Btn").addEventListener("click", () => {
         let a = 22;
         sampleEle.innerHTML ="Accessing variable a inside block = " + a + "<br>";
      try {
         sampleEle.innerHTML = "Accessing variable a outside block = " + a;
      } catch (err) {
         sampleEle.innerHTML +="Accessig variable a outside the block = " + err;


On clicking the ‘CLICK HERE’ button −

Updated on 11-May-2020 13:25:57