What are associative Arrays in JavaScript?

JavascriptWeb DevelopmentObject Oriented Programming

Associative arrays are basically objects in JavaScript where indexes are replaced by user defined keys. They do not have a length property like normal array and cannot be traversed using normal for loop.

Following is the code for associative arrays 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;
   }
</style>
</head>
<body>
<h1>Associative array in JavaScript</h1>
<div style="color: green;" class="result"></div>
<button class="Btn">CLICK HERE</button>
<h3>
Click on the above button to create a associative array and display it
</h3>
<script>
   let resEle = document.querySelector(".result");
   document.querySelector(".Btn").addEventListener("click", () => {
      let arr = { Name: "Rohan", Class: 9, Age: 16 };
      for (i in arr) {
         resEle.innerHTML += "Key = " + i + " : Value = " + arr[i] + "<br>";
      }
   });
</script>
</body>
</html>

Output

The above code will produce the following output −

On clicking the ‘CLICK HERE’ button −

raja
Published on 15-Jul-2020 13:44:23
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