calloc Function

Allocates an array in memory and initializes the elements to 0.

Include

<stdlib.h>

Prototype

void *calloc(size_t nelem, size_t size);

Arguments

Return Value

Returns a pointer to the allocated space if successful; otherwise, returns a null pointer.

Remarks

Memory returned by calloc is aligned correctly for any size data element and is initialized to zero. This function requires a heap.

Example

/* This program allocates memory for the      */
/* array 'i' of long integers and initializes */
/* them to zero.                              */

#include <stdio.h>  /* for printf, NULL */
#include <stdlib.h> /* for calloc, free */

int main(void)
{
  int x;
  long *i;

  i = (long *)calloc(5, sizeof(long));
  if (i != NULL)
  {
    for (x = 0; x < 5; x++)
      printf("i[%d] = %ld\n", x, i[x]);
    free(i);
  }
  else
    printf("Cannot allocate memory\n");
}

Example Output

i[0] = 0
i[1] = 0
i[2] = 0
i[3] = 0
i[4] = 0