Weird outputs with simple Arithmetic C++

Question

If I give this program a string as in input it gives me some very strange outputs. How do I go about handling this? I'd like it to simply state that there was an error on the consul.

#include <cstdlib> 
#include <iostream>

using namespace std;

int main() 

{ 
    cout << endl;
    cout << "Homework (out of 70 pts):  " ;
    int HW ;
    cin >> HW ;

    cout << "Midterm (out of 100 pts):  " ;
    int MT ;
    cin >> MT ;

    cout << "Final (out of 100 pts):    " ;
    int F ;
    cin >> F ;
    cout << endl;

    int S;
    S = HW + MT + F;



    cout << "Score:     " << S << endl;
    cout << endl; 

    system("pause");
}

What exactly was weird and what error did you get on your console? — Marat Salikhov, Sep 03 '10 at 19:12
Are you saying you entered, say, "foo" to one of the numeric inputs, and got odd results? — David Thornley, Sep 03 '10 at 19:13
possible duplicate of [How to validate numeric input C++](http://stackoverflow.com/questions/514420/how-to-validate-numeric-input-c) — David Thornley, Sep 03 '10 at 19:46
A similar StackOverflow question with an answer is [here](http://stackoverflow.com/questions/514420/how-to-validate-numeric-input-c) — mmonem, Sep 03 '10 at 19:20

score 4 · Accepted Answer · edited May 23 '17 at 11:55

4

When you enter a value that cin isn't expecting, such as a string instead of a number, nothing will be read into your variable and cin will set an error flag that will prevent any further input. See my answer to another question on the very same topic.

edited May 23 '17 at 11:55

Community

1
1

answered Sep 03 '10 at 19:15

casablanca

69,683
7
133
150

Weird outputs with simple Arithmetic C++

1 Answers1