How to check canvas is empty or not in javascript

[pravin rasal]

How do I check if there is a data or something is drawn on a canvas?

I have this <canvas id="my_canvas"></canvas>

element and i wanted to check if my canvas has something drawn on it.

[Kavisha Paranamana]

I am not sure if this works in HTML 5 elements. But how about having a jquery test as below? : if($('#my_canvas').html().length == 0){ }