Write a program using pointer to compare two strings.

#include<stdio.h>

int compare_string(char*, char*);

main()

{

    char first[100], second[100], result;

    printf("Enter first string\n");

    gets(first);

    printf("Enter second string\n");

    gets(second);

    result = compare_string(first, second);

    if ( result == 0 )

      printf("Both strings are same.\n");

    else

      printf("Entered strings are not equal.\n");

    return 0;

}

int compare_string(char *first, char *second)

{

  while(*first==*second)

  {

     if ( *first == '\0' || *second == '\0' )

        break;

     first++;

     second++;

  }

  if( *first == '\0' && *second == '\0' )

     return 0;

  else

     return -1;

}

Output:

Enter first String:HI

Enter Second String:HI

Both string are same