Can we check if a property is in an object with JavaScript?

Following is the code to check if a property is in an object 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;
   .result {
      font-size: 20px;
      font-weight: 500;
      color: blueviolet;
<h1>Checking a property in an object</h1>
<div class="result"></div>
<button class="Btn">CLICK HERE</button>
<h3>Click on the above button to check if firstName property is present in obj object</h3>
   let resEle = document.querySelector(".result");
   let obj = { firstName: "Rohan", lastName: "Sharma", age: 21 };
   document.querySelector(".Btn").addEventListener("click", () => {
      if (obj.hasOwnProperty("firstName")) {
         resEle.innerHTML = "Object obj has firstName property";
      } else {
         resEle.innerHTML = "Object obj does not have firstName property";


On clicking the ‘CLICK HERE’ button −