calloc - Allocate and Zero

calloc - Allocate and Zero

calloc allocates memory like malloc, but also zeroes every byte.

The call

int *nums = (int *)calloc(5, sizeof(int));

• First argument: number of elements.
• Second: size of each element.

The difference from malloc

calloc(5, sizeof(int)) allocates 5 ints and sets them all to 0. malloc leaves the memory as garbage.

When use calloc

• When you want zeroed arrays right away.
• Safer for beginners, no surprise garbage.

It still needs free

free(nums);

TL;DR

• calloc = allocate + zero.
• Take element count and element size.
• malloc leaves garbage; calloc clears it.
• Free it when finished.