Fastest way to zero out a 2d array in C?

Question

I want to repeatedly zero a large 2d array in C. This is what I do at the moment:

// Array of size n * m, where n may not equal m
for(j = 0; j < n; j++)
{
            


        

Answer 1

How was your 2D array declared?

If it something like:

int arr[20][30];

You can zero it by doing:

memset(arr, sizeof(int)*20*30);