Thread: Grading in c++

As was said, it should be char not an int.
Also, in your if you use "=". That set's it equal to something. To check for equality you want "==". And you do not use switch and statments at the same time. You can use if statements in switch statements, but not both to decide what to do how you have it done.

just use "toupper" whenever the user enters the grade, and always test for capital letters.. it'll save you 50% of the "OR" statements...

i have no idea what toupper is. also i tried using it and it came up with an error.

Code:

//adds the iostream library to the program
#include <iostream>
//adds the iomanip library to the program
#include <iomanip>
//adds the math library to the program
#include <cmath>
// this one is for the system library =)
#include <cstdlib>


 
//informs the compiler you are using the standard library set
using namespace std;

int main ()
{

  char LetterGrade;
  cout << "Mini Program 5.2\n";
  cout << "Enter the letter grade:  ";
  cin >> LetterGrade;
  cout << endl;
  switch(LetterGrade)
{
     if (LetterGrade == 'A' || LetterGrade == 'a')
          case 'A' && 'a' : cout << "a perfect score.  Excellent." << endl; break;
     else if (LetterGrade == 'B' || LetterGrade == 'b') 
          case 'B' : cout << "well above average.  Keep up the good work. " << endl;break;
     else if (LetterGrade == 'C' || LetterGrade == 'c')
         case 'C' : cout << "average: keep trying you will get there." << endl;break;
     else if (LetterGrade == 'D' || LetterGrade == 'd')
          case 'D' : cout << "below average: seems you need some extra help." << endl;break;
     else if (LetterGrade == 'F' || LetterGrade == 'f')
          case 'f' : cout << "not passing: spend some more time asking questions and make sure you understand the material ahead of time." << endl;break;
     else 
          default  : cout << "LETTER DOES NOT EXIST" << endl; break;
}
    system("pause");
return 0;
}

Here ya go:

Code:

//adds the iostream library to the program
#include <iostream>
//adds the iomanip library to the program
#include <iomanip>
//adds the math library to the program
#include <cmath>
// this one is for the system library =)
#include <cstdlib>
#include <cctype>


 
//informs the compiler you are using the standard library set
using namespace std;

int main ()
{

  char LetterGrade;
  cout << "Mini Program 5.2\n";
  cout << "Enter the letter grade:  ";
  cin >> LetterGrade;
  cout << endl;

  LetterGrade = toupper(LetterGrade); //This makes sure it is upper case to make checking easier.
  //You can also use tolower..they are in the <cctype> library...but how you are doing it is fine.

     if (LetterGrade == 'A' ) //As you see now with toupper even if you input a lower case a this will work
           cout << "a perfect score.  Excellent." << endl; 

     else if (LetterGrade == 'B' || LetterGrade == 'b') 
          cout << "well above average.  Keep up the good work. " << endl;

     else if (LetterGrade == 'C' || LetterGrade == 'c')
         cout << "average: keep trying you will get there." << endl;

     else if (LetterGrade == 'D' || LetterGrade == 'd')
           cout << "below average: seems you need some extra help." << endl;

     else if (LetterGrade == 'F' || LetterGrade == 'f')
           cout << "not passing: spend some more time asking questions and make sure you understand the material ahead of time." << endl;

     else 
         cout << "LETTER DOES NOT EXIST" << endl;

    system("pause");
return 0;
}

Notice the comments in the code about toupper. It is just nice but your method is perfectly fine. Notice how I removed all the switch statements. You do not need them if you are going to use the if else if statements.

It now works just fine.

One comment. You include a lot of libraries you do not use. Be careful with that.

You should not combine the switch and if. Pick one. I'd pick the if because you've got the code for it already there. If you pick the switch, you have to have a separate case for 'A' and 'a'.

Yes, bit with switch statements you can have the cases together.
example.

Code:

switch (LetterGrade)
{
     case 'A':
     case 'a': cout << "A perfect score. Excellent" << endl; break:

.......
}

So, if you did not do the toupper or to lower, then if they entered either A or a they both get the same data.

Switch statements are really just very limited if else statements. If else has more flexibility that switch though. Make sure to learn how to properly use if else statements as well.