Difference between document.ready and window.onload

Both document.ready and window.onload event is used to perform the action when webpage is loaded. What’s the difference between these two events.

The difference between document.ready and window.onload is most asked javascript interview question for both fresher and experienced web developers.

Difference Between Undefined and Null Value in Javascript

What’s the difference between an undefined and null value in Javascript. If you are new to  Javascript, probably you will find difficulty in understanding the difference between undefined and null value. How to check whether a variable is undefined or null.