Malloc and It’s Implementation in C

Malloc: In computing, malloc is a function or subroutine for performing dynamic memory allocation in the C and C++ programming languages. malloc is part of the standard library for both languages and is declared in the stdlib.h header although it is also declared within the std namespace via the C++’s cstdlib header.
function prototype of malloc is

void *malloc(size_t size);

Example:  Here given a C program

#include <stdio.h>

#include <stdlib.h>

 int main ()

{

  int i,n;

  char * buffer;

  printf ("How long do you want the string? ");

  scanf ("%d", &i);

   buffer = (char*) malloc (i+1);

  if (buffer==NULL) exit (1);

   for (n=0; n<i; n++)

    buffer[n]=rand()%26+'a';

  buffer[i]='\0';

   printf ("Random string: %s\n",buffer);

  free (buffer);

   return 0;

}

Thank you.