Lohith Nayak

• Jun 8th, 2007

 

calloc(NULL, 2) = malloc(2).

calloc(NULL,0) = malloc(0).

kannan987

 Profile Answers by kannan987 

• Jun 13th, 2008

 

It Allocates Some memory..

 #include "test.h"


int main(void)
{
    int *p = NULL;
 int *c =(int*)malloc(sizeof(p));
 printf("%0x",&c);
 return 0;

}

o/p : return some memory address

kannan987

 Profile Answers by kannan987 

• Jun 13th, 2008

 

test.h is nothing but in my pgm..

simply include all header files..

<----test.h--->

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<string.h>

kbjarnason

 Profile Answers by kbjarnason 

• Jul 1st, 2010

 

You don't pass null pointers to malloc or calloc.  You can pass them to realloc.

Perhaps you mean what would happen if you did this:

#include <stdlib.h>

int main(void)
{
   char *ptr = NULL;

    ptr = malloc(100);

    if ( ptr )
      free( ptr );

   return 0;
}


In this case, the fact that ptr is NULL when you call malloc is really irrelevant, since all you're doing is assigning malloc's return value to ptr anyhow.


Side note: in C, do *not* cast the return value of malloc.  It returns a void pointer, which is type compatible with anything you're going to be meaningfully assigning to, and the cast can cause the compiler to overlook a potentially disastrous bug.