String Addition using pointers, functions and loop

String concatenation is a way to add two strings. For example if we have two strings "My" and "Name" then to produce these two strings as one string that is "My Name", we will concatenate these two strings. We can do concatenation in C Programming Language by using built-in string concatenation function defined in <String.h> library but we can also make our own function to concatenate two strings. The following code do concatenation of two strings using pointers, functions and loops.

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

void concatenate_string(char*, char*);

int main()
{
    char original[100], add[100];

    printf("Enter source string\n");
    gets(original);

    printf("Enter string to concatenate\n");
    gets(add);

    concatenate_string(original, add);

    printf("String after concatenation is \"%s\"\n", original);
 getch();
    return 0;
}

void concatenate_string(char *original, char *add)
{
   while(*original)
      original++;

   while(*add)
   {
      *original = *add;
      add++;
      original++;
   }
   *original = '\0';
}