Hi, how do you count the number of null in a 2d array in data and return 0 if data is null or empty and how do you count non number of non-null in 2d arrays in data, and return 0 if data is null or empty. I cannot use inbuilt libraries or hard code either question

public int countNullSubarrays(int[][] data) { return 0; //to be completed }

public int countNonNullSubarrays(int[][] data) { return 0; }