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

JavascriptWeb DevelopmentObject Oriented Programming

Following is the code to check if a property is in an object in JavaScript −

Example

 Live Demo

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
   body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
   }
   .result {
      font-size: 20px;
      font-weight: 500;
      color: blueviolet;
   }
</style>
</head>
<body>
<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>
<script>
   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";
      }
   });
</script>
</body>
</html>

Output

On clicking the ‘CLICK HERE’ button −

raja
Published on 17-Jul-2020 11:44:58
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