JavaScript does not support Associative array. Arrays in JavaScript work with numbered indexes. Here is an example −
Example
<!DOCTYPE html>
<html>
<body>
<p id="test"></p>
<script>
var dept = [];
dept[0] = "Amit";
dept[1] = "Technical";
dept[2] = 045;
document.getElementById("test").innerHTML = dept[1] + " " + dept.length;
</script>
</body>
</html>