I'm trying to make a program in C in which you can play hangman but as soon as it prints the option to guess the letter the program terminates

Question

The program isn't printing after giving me the first chance to guess.

#include <stdio.h>
#include <string.h>
int main() {
    char menu;
    int c = 0, flag = 0, life = 8;

    printf("\nWelcome to Hangman!!!");
    printf("\nThis is a game of hangman.");
    printf("Player 1 enters a random word and the other has to guess it.");
    printf("You get 8 lives in total i.e. you can have a maximum of 8 wrong guesses.");
    printf("\n");
    printf("Press n for new game\n");
    printf("Press q to quit\n");
    printf("\n");

    scanf("%c", &menu);
    int i = 0, j = 0;
    char w[20], ch;

    if (menu == 'q') {
        printf("Exiting...");
        printf("Thanks for playing");
    }
    else if (menu == 'n') {
        printf("Player 1 enters a word\n");
        scanf("%s", w);
        int len = strlen(w);

        for (int i = 0; i < len; i++) {
            toupper(w[i]);
        }

        printf("\e[1;1H\e[2J");
        char arr[len - 1];

        for (int i = 0; i < len - 1; i++) {
            arr[i] = '_';
            printf("%c", arr[i]);
        }

        printf("\n");

        while (life != 0) {
            for (int i = 0; i < len - 1; i++) {
                if (arr[i] == '_') {
                    flag = 1;
                    break;
                }
                else {
                    flag = 0;
                }
            }

            if (flag == 0) {
                printf("You Won!!\n");
                printf("You Guessed The Word: %s", w);
                break;
            }
            else {
                char ans;
                printf("Enter a letter between A-Z");
                scanf("%c", ans);
                toupper(ans);
                
                for (int j = 0; j < len; j++) {
                    if (ans == w[j]) {
                        arr[j] = ans;
                        c++;
                    }
                }

                if (c == 0) {
                    life--;
                }

                c = 0;

                for (int j = 0; j < len; j++) {
                    printf("%c", arr[j]);
                }

                printf("\n Lives Remaining= %d \n", life);
            }
        }

        if (life == 0) {
            printf("\n You Lost!!! \n");
            printf("The Word Was: %s", w);
        }
    }
    else {
        printf("Invalid Character");
    }
}

Output:
Welcome to Hangman!!!
This is a game of hangman.Player 1 enters a random word and the other has to >guess it.You get 8 lives in total i.e. you can have a maximum of 8 wrong >guesses.
Press n for new game
Press q to quit

n
Player 1 enters a word
Hello

Enter a letter between A-Z PS C:\Users\arora\Desktop\Programs\C>

Does this answer your question? [scanf() leaves the newline character in the buffer](https://stackoverflow.com/questions/5240789/scanf-leaves-the-newline-character-in-the-buffer) — Retired Ninja, Sep 07 '22 at 04:26
`scanf()` was not designed for user input. Use `fgets()` instead. — pmg, Sep 07 '22 at 16:04

Allan Wind · Accepted Answer · 2022-09-08T07:19:19.083

There are quite a few problems with your program. Here are the major ones:

You want to use use space prefix in the format string for scanf(" %c", ...) to ensure previous newlines are ignored.
scanf("%c", ans); should be &ans. It causes scanf() to fail rendering the remain of the program non-interactive. Without input from the user the core game logic doesn't work.

Here are some of the other issues:

#include <ctype.h>.
(not fixed) Consider changing the menu logic so 'q' quits, and any other letter starts a game.
Game prompt contains long lines that are hard to read for the player(s).
You use a printf() per line which makes it hard to read. Use a single call and multi-line strings as input.
Try to branch your code less by making use of early return. It makes it easier to read.
Check the return value of scanf(). If it fails then whatever variable it read doesn't have a well defined value.
Ensure that scanf() read no more than 19 bytes into a 20 byte array w. It takes a little macro magic to generate the 19 so I didn't make this change but it's a good idea to #define constants for magic values like the 20.
arr is not \0 terminated (len-1). Most c programmers expect a string so it's not worth the confusion to save 1 byte.
Use a function or macro for the ANSI escape to clear the screen.
Eliminate unused variables i, j.
Reduce scope of variables (declare variables close to where you use them).
The calculation of the flag variable is cumbersome.
(not fixed) The prompt "Enter a letter between A-Z" is somewhat ambiguous. Suggest "... between A and Z".
It's generally a good idea to leave user input as you read. If you care about the repeated toupper() you can create a copy of the user input with letters in upper case, and create another variable to hold the upper case version of the player's guess. This avoid you saying things like you entered the word "BOB" when the actual input was "bob".
You attempt to use toupper() to convert each letter to upper case but don't assign the result to anything so it does not do anything constructive.
Consider some functions to document what each your code does. I added some comments for now.
(mostly not fixed) Consider using better variable names (c, w, arr, flag).
(not fixed) Should you reject a word with your magic '_' value? In general should you validate that the word is reasonable (a-z, len > 0, len < 20)?
(not fixed) Consider, in arr, just storing if a letter was correctly guess (boolean). When evaluating the state show the letter from w if it is already guessed otherwise the _.
(not fixed) If you guess a correct letter again, it's considered a good guess. Should it?

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

#define clear() printf("\e[1;1H\e[2J")

int main() {
    printf(
        "Welcome to Hangman!!!\n"
        "\n"
        "This is a game of hangman.\n"
        "Player 1 enters a random word and the other has to guess it.\n"
        "You get 8 lives in total i.e. you can have a maximum of 8 wrong guesses.\n"
        "\n"
        "Press n for new game\n"
        "Press q to quit\n"
    );
    char menu;
    if(scanf(" %c",&menu) != 1) {
        printf("scanf failed\n");
        return 1;
    }
    switch(menu) {
    case 'q':
        printf(
            "Exiting..."
            "Thanks for playing\n"
        );
        return 0;
    case 'n':
        break;
    default:
        printf("Invalid Character");
        return 1;
    }

    printf("Player 1 enters a word\n");
    char w[20];
    if(scanf("%19s", w) != 1) {
        printf("scanf failed\n");
        return 1;
    }
    clear();

    char arr[20];
    int len=strlen(w);
    for(int i=0;i<len;i++) {
        arr[i]='_';
    }
    arr[len] = '\0';
    int life=8;
    for(;;) {
        printf("%d Lives Remaining\n", life);

        // read a guess from player
        for(int i = 0; i < len; i++) {
            printf("%c", arr[i]);
        }
        printf(" Enter a letter between A-Z ");
        char guess;
        if(scanf(" %c", &guess) != 1) {
            printf("scanf failed\n");
            return 1;
        }

        // determine if any of the letters are in the secret word
        int c = 0;
        for(int i=0; i<len; i++) {
            if(toupper(guess) == toupper(w[i])) {
                arr[i]=guess;
                c = 1;
            }
        }
        if(c==0) {
            life--;
        }

        // game over?
        int flag = 0;
        for(int i = 0; i<len; i++) {
            if(arr[i]=='_') {
                flag=1;
                break;
            }
        }
        if(flag==0) {
            printf("You Won!!\n");
            printf("You Guessed The Word: %s\n",w);
            break;
        }
        if(life==0) {
            printf("\n You Lost!!!\n");
            printf("The Word Was: %s\n", w);
            break;
        }
    }
}

I'm trying to make a program in C in which you can play hangman but as soon as it prints the option to guess the letter the program terminates

1 Answers1