Variables cannot be clear

Question

So I wrote these codes when I ran it and input the right answer, it works perfectly fine, but if I put the wrong answer and use the while loop to run the program again, it outcome will store the last input and does not let me input anymore.

I found out that you can add guess.clear(); to clear the memory which is stored in the variable "guess".

#include <iostream>
#include <string>
#include <inttypes.h>

using namespace std;

int main(){

    int replay = 0;
    int input = 0;

    while(input == replay){
        string celebrity = "Keeves Reeves";
        string guess;
        guess.clear();


        cout << "Hint: He acted as John Wick." << endl;
        cout << "Guess who's this celebrity is: ";
        getline(cin, guess);


        if(guess == celebrity){
            cout << "Congratulations! You got it!\n" << endl;
            input = 2;
        } else if(guess != celebrity){
            cout << "Whoops, that not the right answer..." << endl;
            cout << "Do you want to try again? Enter '0' to replay or enter '1' to view the answer: ";
            cin >> input;
            if (input == 1){
                cout << "The answer is " + celebrity  + "." << endl;
                input = 2;
            }
        }
    }


    cout << "Thank you for playing. The end." << endl;
    system("pause");

    return 0;
}

Outcome:

Hint: He acted as John Wick.
Guess who's this celebrity is: Michael
Whoops, that not the right answer...
Do you want to try again? Enter '0' to replay or enter '1' to view the answer: 0
Hint: He acted as John Wick.
Guess who's this celebrity is: Whoops, that not the right answer...
Do you want to try again? Enter '0' to replay or enter '1' to view the answer:

score 1 · Accepted Answer · answered Oct 13 '19 at 07:22

If you are using getline() you could add the cin.ignore() to clear the buffer would look like:

int main(){

    int replay = 0;
    int input = 0;

    while(input == replay){
        string celebrity = "Keeves Reeves";
        string guess;
        //guess.clear();


        cout << "Hint: He acted as John Wick." << endl;
        cout << "Guess who's this celebrity is: ";
        getline(cin, guess);


        if(guess == celebrity){
            cout << "Congratulations! You got it!\n" << endl;
            input = 2;
        } else if(guess != celebrity){
            cout << "Whoops, that not the right answer..." << endl;
            cout << "Do you want to try again? Enter '0' to replay or enter '1' to view the answer: ";
            cin >> input;
            cin.ignore()  // here add the ignore() function.
            if (input == 1){
                cout << "The answer is " + celebrity  + "." << endl;
                input = 2;
            }
        }
    }
    cout << "Thank you for playing. The end." << endl;    
}

I wonder what's "buffer" means? Also, I wonder what .clear() do, does it like clear the string that is stored in the string variable? — FlashSonic526, Oct 13 '19 at 07:27
see: https://stackoverflow.com/questions/5131647/why-would-we-call-cin-clear-and-cin-ignore-after-reading-input — Josh W., Oct 13 '19 at 07:52

score 0 · Answer 2 · edited Oct 13 '19 at 07:35

Is using getline necessary for you? It'll work as intended by using cin >> guess.

Code:

int replay = 0;
int input = 0;

while (input == replay) {
    string celebrity = "Keeves Reeves";
    string guess = "";

    cout << "Hint: He acted as John Wick." << endl;
    cout << "Guess who's this celebrity is: ";
    cin >> guess;


    if (guess == celebrity) {
        cout << "Congratulations! You got it!\n" << endl;
        input = 2;
    }
    else if (guess != celebrity) {
        cout << "Whoops, that not the right answer..." << endl;
        cout << "Do you want to try again? Enter '0' to replay or enter '1' to view the answer: ";
        cin >> input;
        if (input == 1) {
            cout << "The answer is " + celebrity + "." << endl;
            input = 2;
        }
    }
}


cout << "Thank you for playing. The end." << endl;
system("pause");

return 0;

}

Output:

Guess who's this celebrity is: a
Whoops, that not the right answer...
Do you want to try again? Enter '0' to replay or enter '1' to view the answer: 0
Hint: He acted as John Wick.
Guess who's this celebrity is: a
Whoops, that not the right answer...
Do you want to try again? Enter '0' to replay or enter '1' to view the answer: 0
Hint: He acted as John Wick.
Guess who's this celebrity is: a
Whoops, that not the right answer...
Do you want to try again? Enter '0' to replay or enter '1' to view the answer: 1
The answer is Keeves Reeves.
Thank you for playing. The end.
Press any key to continue . . .```

Probably `cin >> str; ` cannot get strings with spaces. For example, the input "Keeves ASDF" will also considered as an answer. — user5876164, Oct 13 '19 at 07:12
I see, thank you. I somehow remember cin.ignore(); and it also works, thank you. — FlashSonic526, Oct 13 '19 at 07:15

Variables cannot be clear

2 Answers2