CODEWITHSUNDEEP
c++random
zebercet
zebercet

Reputation: 13

Can't exit the while loop after guessing the right number

I'm trying to make a simple number guessing program with while loop but even after finding the right number (I changed the num with 5 and it didn't work) it does not exit the while loop. Can you tell me where the problem is?

int guess;
int num;

cout << "Enter the number (0-10): ";
cin >> guess;

while(guess != num){
    int num = rand()%10;
    cout << "Nope, keep trying." << endl;
    cout << "Enter the number (0-10): ";
    cin >> guess;
}

cout << "Congrats, you've found the number!" << endl;

Upvotes: 0

Views: 122

Answers (2)

Remy Lebeau
Remy Lebeau

Reputation: 596307

The while loop is evaluating a num variable that is never assigned a value. The assignment being done inside the loop is to a different num variable that shadows the outer variable of the same name.

Try this instead:

#include <iostream>
#include <limits>
#include <cstdlib>
using namespace std;

int main() {
    int guess;
    int num;

    do {
        cout << "Enter the number (0-10): ";
        if (cin >> guess) {
            if (guess == num)
                break;
            num = rand() % 10;
            cout << "Nope, keep trying." << endl;
        }
        else {
            cin.clear();
            cin.ignore(numeric_limits<streamsize>::max(), '\n');
            cout << "Not a number, keep trying." << endl;
        }
    }
    while (true);

    cout << "Congrats, you've found the number!" << endl;
}

Upvotes: 0

Bathsheba
Bathsheba

Reputation: 234715

int num = rand() % 10; is a declaration of a new variable num within the loop body and that shadows the num defined at the top of the program: while (guess != num) is using the latter.

The solution is to write num = rand() % 10; instead.

You will need to initialise num to a value before attempting to read it, else technically the behaviour of your program is undefined. Consider reworking to a do while loop.

Upvotes: 5

Related Questions