c++ int switch statement

Question

i have been working on a switch for integers for the last hour and a half now, i know how to do switch with char but this seems much hard for me.any advice will be appreciated.the problem i have is that i cant accept grades over 100 which this switch currently does

    int testScore;                     
    cout <<"Enter your test score and I will tell you \n";
    cout <<"the letter grade you earned ";
    cin >> testScore;

    switch(testScore/10)
{ 
    case 10:
    case 9:
        cout <<"Your grade is A.\n";
    break;
    case 8: 
        cout <<"Your grade is B.\n";
    break;
    case 7: 
        cout <<"Your grade is C.\n";
        break;
    case 6: 
            cout << "Your grade is D.\n";
        break;
    case 5: 
            cout << "Your grade is F.\n";
        break;

    default:
        cout << "That score isn’t valid\n";

    }

Solution 1

You're dividing by 10.0, which is a double and this will not compile. This has to be changed to 10. Also, you should precede the switch statement with an if statement that checks if it's in a valid range.

#include<iostream>
#include<iomanip>
using namespace std;
int main() 
{

int testScore;
cout <<"Enter your test score and I will tell you \n";
cout <<"the letter grade you earned \n";
cin >> testScore;

if (testScore<=100 && testScore>=0)
    switch(testScore/10)
    {
        case 10:
        case 9:
            cout <<"Your grade is A.\n";
            break;
        case 8:
            cout <<"Your grade is B.\n";
            break;
        case 7:
            cout <<"Your grade is C.\n";
            break;
        case 6:
            cout << "Your grade is D.\n";
            break;
        case 5:
            cout << "Your grade is F.\n";
            break;

        default:
            cout << "That score isn’t valid\n";
    }
else
    cout <<"That score isn't valid\n";

return 0;
}

Solution 2

You really should do this with 'if' not a 'switch'. Something like the following code (not tested):

if (testScore >=0 && testScore <= 100)
{
    char grade;

    if (testScore >= 90)
        grade = 'A';
    else if (testScore >= 80)
        grade = 'B';
    else if (testScore >= 70)
        grade = 'C';
    else if (testScore >= 60)
        grade = 'D';
    else
        grade = 'F';

    cout << "Your grade is " << grade << endl;
}
else
{
    cout << "Score of " << testScore << " is not valid" << endl;
}

Comments

[Jose Meza]

i tried this and it still shows me a grade of A for numbers 100-109

[jliv902]

This should be a comment, this does not answer the question.

[Max Lybbert]

In C++ (and many other languages), dividing the integer 109 by the integer 10 returns 10, which will trigger the first case. If you don't want people entering numbers larger than 100, you'll need to enforce that somewhere. For instance, between the line you use cin and the switch statement.

[Seyon]

Fair enough. In response to the question though, you can have an if statement if (testScore<=100 && testScore>=0) which executes the switch statement if true and outputs Test Score not valid if false

[jliv902]

@Borat.sagdiyev You should put that into your answer.