Check if object exists in JavaScript

Question

How do I verify the existence of an object in JavaScript?

The following works:

if (!null)
   alert(\"GOT HERE\");

But this throws a

Answer 1

You can safely use the typeof operator on undefined variables.

If it has been assigned any value, including null, typeof will return something other than undefined. typeof always returns a string.

Therefore

if (typeof maybeObject != "undefined") {
   alert("GOT THERE");
}