How to check a 2D matrix is empty?

Question

I think that all we need is

if (matrix.length == 0)

However, I saw some of them write

if (matrix == null || matrix.length == 0 || matrix[0].length == 0) 

Is my version enough to check a matrix is empty or not or we need to write the above version?

Answer 1

You will get a NullPointerException if you call matrix.length() if matrix is null, that's why the second check is better.