function

free

<cstdlib>
void free ( void * ptr );
Deallocate space in memory
A block of memory previously allocated using a call to malloc, calloc or realloc is deallocated, making it available again for further allocations.

If ptr does not point to a block of memory allocated with the above functions, the behavior is undefined.

If ptr is a null pointer, the function does nothing.

Notice that this function does not change the value of ptr itself, hence it still points to the same (now invalid) location.

Parameters

ptr
Pointer to a memory block previously allocated with malloc, calloc or realloc.

Return Value

(none)

Example

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/* free example */
#include <stdio.h>
#include <stdlib.h>

int main ()
{
  int * buffer1, * buffer2, * buffer3;
  buffer1 = (int*) malloc (100*sizeof(int));
  buffer2 = (int*) calloc (100,sizeof(int));
  buffer3 = (int*) realloc (buffer2,500*sizeof(int));
  free (buffer1);
  free (buffer3);
  return 0;
}


This program has no output. It just demonstrates some ways to allocate and free dynamic memory using the C stdlib functions.

See also

malloc
Allocate memory block (function )
calloc
Allocate space for array in memory (function )
realloc
Reallocate memory block (function )

C++