Incorrect printout from while loop

[Cpluswhat]

I am making a hangman program. It displays the word "PROGRAMMING" as all *'s and replaces a * with the correct letter if that letter is guessed. I am trying to set it so that it only allows 7 errors before the player loses.

My program keeps printing the output twice after each guess, and since I have added the "else" statement it automatically prints "WRONG" 7 times and ends the program instead of just adding one the int wrong.

Can anyone tell me why I am having these errors?

#include "stdafx.h"
#include <stdio.h>
#include <string.h>
#include <ctype.h>


char word[]= "PROGRAMMING"; //The correct word
char guessed[] = "***********"; //blanks for the word
char letter; //letter to be guessed
int wrong; //counter for how many attempts have been made


int main(void)
{
	int wordlength = strlen(word);
	int i = 0;	//use i as a counter in for loops
	
	printf("Welcome to Hangman.\n\n\n"); //title
	
	while (guessed != word && wrong < 7) //loop until the whole word is guessed or too many attempts are made
		{
			printf("\n"); //for spacing
			printf("Word:  %s\n", &guessed); //show word guessed so far
			printf("Guess a letter: "); //ask for a letter
			scanf("%c", &letter); //scan for the letter
			letter = toupper(letter); //set letter to uppercase

			for (i = 0; i < wordlength; i++) //loop through the word and see if letter guessed is within it						 
			{
					if (letter == word[i]) 
					{ 
					guessed[i] = letter;// if it is, replace the * with the letter
					}
					else
					{
						printf("WRONG!");
						wrong += 1; //add one more attempt
					}

			}
		}

	if (guessed == word)  //If word was guessed, congrats to the winner
		printf("Congratulations! You WIN!!!!!\n");
	else
		printf("Too many incorrect guesses. You are dead.\n"); //too many guesses

	return 0;
}

[jdd]

Inspect this loop:

for (i = 0; i < wordlength; i++) //loop through the word and see if letter guessed is within it
{
	if (letter == word[i]) 
	{ 
	guessed[i] = letter;// if it is, replace the * with the letter
	}
	else
	{
		printf("WRONG!");
		wrong += 1; //add one more attempt
	}

}

It searches word one char at a time, and for each char that is incorrect in increments wrong. For example, if you guess the
letter 'P' you would end up with 10 wrong guesses.

[Cpluswhat]

Ok, I changed the code so it just counts all attempts made and counters at the end of the while loop.
But, it still doesn't exit the loop when the word has been guessed correctly and it still prints the output twice after each letter is entered...

#include "stdafx.h"
#include <stdio.h>
#include <string.h>
#include <ctype.h>


char word[]= "PROGRAMMING"; //The correct word
char guessed[] = "***********"; //blanks for the word
char letter; //letter to be guessed
int attempt; //counter for how many attempts have been made


int main(void)
{
	int wordlength = strlen(word);
	int i = 0;	//use i as a counter in for loops
	
	printf("Welcome to Hangman.\n\n\n"); //title
	
	while (guessed != word && attempt < 20) //loop until the whole word is guessed or too many attempts are made
		{
			printf("\n"); //for spacing
			printf("Word:  %s\n\n", &guessed); //show word guessed so far
			printf("Guess a letter: "); //ask for a letter
			scanf("%c", &letter); //scan for the letter
			letter = toupper(letter); //set letter to uppercase

			for (i = 0; i < wordlength; i++) //loop through the word and see if letter guessed is within it						 
			{
					if (letter == word[i]) 
					{ 
					guessed[i] = letter;// if it is, replace the * with the letter
					}
					
			}
			attempt += 1;
		}

	if (guessed == word)  //If word was guessed, congrats to the winner
		printf("Congratulations! You WIN!!!!!\n");
	else
		printf("Too many incorrect guesses. You are dead.\n"); //too many guesses

	return 0;
}

[jdd]

You can't compare two c strings by simply using != and == (see lines 20 and 39). Someone else would have to verify this, but I believe that compares their pointers. You can, however, use strcmp. Strcmp is a little different from normal functions in that it returns zero if the two strings are equal, and a value other than zero if they are not.
http://www.cplusplus.com/reference/clibrary/cstring/strcmp.html

[Cpluswhat]

Thank you. I have fixed the program so that it compares the entire strings.

#include "stdafx.h"
#include <stdio.h>
#include <string.h>
#include <ctype.h>


char word[]= "PROGRAMMING"; //The correct word
char guessed[] = "***********"; //blanks for the word
char letter; //letter to be guessed
int attempt; //counter for how many attempts have been made


int main(void)
{
	int wordlength = strlen(word);
	int i = 0;	//use i as a counter in for loops
	
	printf("Welcome to Hangman.\n\n\n"); //title
	
	while ((strcmp (word, guessed) != 0) && attempt < 20) //loop until the whole word is guessed or too many attempts are made
		{
			printf("\n"); //for spacing
			printf("Word:  %s\n\n", &guessed); //show word guessed so far
			printf("Guess a letter: "); //ask for a letter
			scanf("%c", &letter); //scan for the letter
			letter = toupper(letter); //set letter to uppercase

			for (i = 0; i < wordlength; i++) //loop through the word and see if letter guessed is within it						 
			{
					if (letter == word[i]) 
					{ 
					guessed[i] = letter;// if it is, replace the * with the letter
					}
					
			}
			attempt += 1;
		}

	if (strcmp(word, guessed) == 0)  //If word was guessed, congrats to the winner
		printf("Congratulations! You WIN!!!!!\n");
	else
		printf("Too many incorrect guesses. You are dead.\n"); //too many guesses

	return 0;
}

I am still having a problem with it printing lines 22-24 twice instead of once after each letter is input.

[jdd]

This is a really common problem when using scanf. After you perform scanf, there's still an extra '\n' character in the buffer. This causes scanf to pull out that character during the next iteration, meaning that the loop runs twice for every user input. There are a couple ways to fix it, but I think the easiest is to follow scanf with getchar();

You can avoid a lot of these types of problems by migrating to c++ style i/o functions and strings.
http://www.cplusplus.com/doc/tutorial/basic_io.html

[Cpluswhat]

Ah, I see. I am in a regular C class right now, though, so I have to stick with the basics of C.
Are there any other ways to avoid the double print?
I guess that means it is incrementing the attempt counter twice each time too...

[jdd]

A simple method to debug looping and recursion problems is to insert something like printf("\n*\n"); at certain points in your code. This way you can easily see how your code progresses while the program is running, and you can identify the point(s) where its behavior is not what you intended.

[Cpluswhat]

I am using Visual Studio, and I set a break point just before the while loop and went through it step by step...it runs through the loop once, increments attempt, then goes to the beginning of the while loop again, but doesn't wait for a letter to be entered in scanf, and continues through the loop a second time, incrementing attempt again.

So, it runs twice for each letter entered, not waiting for the user to enter a letter the second time.