How to transform JavaScript arrays using maps?

Javascript Web Development Object Oriented Programming

Following is the code to transform JavaScript arrays using maps.

Example

<!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,.sample {
      font-size: 18px;
      font-weight: 500;
      color: rebeccapurple;
   }
   .result {
      color: red;
   }
</style>
</head>
<body>
<h1>Transform JavaScript arrays using maps</h1>
<div class="sample">[22,33,44,55]</div>
<br />
<div class="result"></div>
<br />
<button class="Btn">CLICK HERE</button>
<h3>Click on the above button to square each element of the above array</h3>
<script>
   let resEle = document.querySelector(".result");
   let BtnEle = document.querySelector(".Btn");
   let arr = [22, 33, 44, 55];
   BtnEle.addEventListener("click", () => {
      resEle.innerHTML = arr.map((a) => a * a);
   });
</script>
</body>
</html>