​x
 
<!DOCTYPE html>
<html>
<body>
​
<h2>JavaScript Objects</h2>
​
<p>To test if an object does not exist, test if the type is undefined:</p>
​
<p id="demo"></p>
​
<script>
document.getElementById("demo").innerHTML = typeof myObj === "undefined";
</script>
​
</body>
</html>
​