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

Use calloc instead of malloc . calloc will initiate all fields to 0.

int *a = (int *)calloc(n,size of(int)) ;

//all cells of a have been initialized to 0