Problems with while and switch loops

Question

I'm having issues with my code. I am trying to build a game and it somehow gives errors when reaching the main loops. I will show to code and the errors I'm getting.

Just a small note, the point when choosing option 1 and playing the game is that the game loops after the correct answer has been given and presents the player with a second random word, and keeps doing this until the player writes 'quit'.

This is the code:

#include <iostream>
#include <string>
#include <cstdlib>
#include <ctime>
using namespace std;

int main()
{
    enum fields {WORD, HINT, NUM_FIELDS};
    const int NUM_WORDS = 3;
    const string WORDS[NUM_WORDS][NUM_FIELDS] =
    {
        {"jumble1", "First word."},
        {"jumble2", "Second word."},
        {"jumble3", "Third word."}
    };

    srand(static_cast<unsigned int>(time(0)));
    int choice = (rand() % NUM_WORDS);
    string theWord = WORDS[choice][WORD];
    string theHint = WORDS[choice][HINT];

    string jumble = theWord;
    int length = jumble.size();
    for (int i = 0; i < length; ++i)
    {
        int index1 = (rand() % length);
        int index2 = (rand() % length);
        char temp = jumble[index1];
        jumble[index1] = jumble[index2];
        jumble[index2] = temp;
    }

    int choice;
    bool choiceNotMade = true;

    while (choiceNotMade)
    {
        cout << "[1] Play\n";
        cout << "[2] Credits\n";
        cout << "[3] Quit\n\n";

                cout << "Your choice: ";
        cin >> choice;
        }

            switch (choice)
            {
            case 1:
                cout << "Unscramble the letters to make a word.\n";
                cout << "Enter 'hint' for a hint.\n";
                cout << "Enter 'quit' to quit the game.\n\n";
                cout << "The jumble is: " << jumble;

                string guess;
                cout << "\n\nYour guess: ";
                cin >> guess;

                while ((guess != theWord) && (guess != "quit"))
                {
                    if (guess == "hint")
                    {
                        cout << theHint;
                    }
                    else
                    {
                        cout << "That's not the right word.";
                    }

                    cout << "\n\nYour guess: ";
                    cin >> guess;
                }

                if (guess == theWord)
                {
                    cout << "\nYou guessed it!\n";
                }

                cout << "\nThank you for playing.\n";

                system("Pause");
                choiceNotMade = false;
                break;

            case 2:
                cout << "\n\nThis game has been made by:\n\n";
                choiceNotMade = false;
                break;

            case 3:
                cout << "Program will exit";
                exit(1);

            default:
                cout << "\nYou did not pick a valid option.\n\n";
                choiceNotMade = false;
                break;  

                } 

    return 0;
}

And this is the error:

word_jumble.cpp: In function `int main()':
word_jumble.cpp:32: error: redeclaration of `int choice'
word_jumble.cpp:17: error: `int choice' previously declared here
word_jumble.cpp:83: error: jump to case label
word_jumble.cpp:53: error:   crosses initialization of `std::string guess'
word_jumble.cpp:88: error: jump to case label
word_jumble.cpp:53: error:   crosses initialization of `std::string guess'
word_jumble.cpp:92: error: jump to case label
word_jumble.cpp:53: error:   crosses initialization of `std::string guess'
word_jumble.cpp:83: warning: destructor needed for `guess'
word_jumble.cpp:83: warning: where case label appears here
word_jumble.cpp:83: warning: (enclose actions of previous case statements requiring destructors in their own scope.)
word_jumble.cpp:88: warning: destructor needed for `guess'
word_jumble.cpp:88: warning: where case label appears here
word_jumble.cpp:92: warning: destructor needed for `guess'
word_jumble.cpp:92: warning: where case label appears here
word_jumble.cpp:100:2: warning: no newline at end of file
make[2]: *** [build/Debug/MinGW-Windows/word_jumble.o] Error 1
make[1]: *** [.build-conf] Error 2
make: *** [.build-impl] Error 2

Answer 1

You are declaring

int choice; 

twice, once

int choice = (rand() % NUM_WORDS);

and then, right before

while (choiceNotMade)

Answer 2

I think the message

redeclaration of `int choice'

should be pretty obvious.

The other error messages are a little harder to understand, but will disappear if you declare the variable guess outside of the switch statement.

Answer 3

I assume that this is a homework, so I'll stay away from too specific recommendations.

You declared the variable choice on line 19, so you need to remove the second declaration at line 34.

You also need to move the declaration of string guess to before the switch statement. This is because C++ requires all locals to be initialized exactly once, and there is no way a compiler could make sure of that if the first time through the loop you take case 2: and the second time around it takes case 1: where string guess is declared.

This will make your program compile, but it would not work as expected. Look at the opening/closing braces in your program, and ensure that the code blocks are nested in the way that you expect.

Answer 4

You have declared choice at two places. Also, you have written the switch outside the while loop which means that even if your program compiles, it will be stuck in an infinite loop.

Answer 5

You're declaring int choice twice. The error message is pretty clear on that.

Once you've declared a variable, you can't re-declare it in the same scope:

{
  int x;

  //...
  int x; // <-- illegal, just use x
}