C++ Program Grading Score Switch

Introduction

In this lab, we will write a C++ program that will take an input score from the end-user and then find the grade based on the given score using the switch case statement.

Create and Open a File

First, we need to create a new file named grade.cpp in the ~/project directory. We will use the touch editor to create the file with the following command:

touch ~/project/grade.cpp

Write the Code

Add the following code to the grade.cpp file:

#include<iostream>
using namespace std;
// function to find grade using switch-case
char findGrade(int score)
{
   // check score is valid or not
   // score is valid if it belongs to 0-100
   if(score<0 || score>100) {
     return '\0';
   }

   // find grade for given score
   switch( score / 10 )
   {
     case 10:
     case 9:
       return 'A';
     case 8:
       return 'B';
     case 7:
       return 'C';
     case 6:
       return 'D';
     case 5:
       return 'E';
     default:
       return 'F';
   }
}
// main function
int main()
{
   // variables
   int score;
   char grade;

   // take score
   cout << "Enter score(0-100): ";
   cin >> score;

   // find grade
   grade = findGrade(score);

   // display grade
   if(grade=='\0')
     cout << "Invalid Score";
   else
     cout << "Grade = " << grade << endl;

   return 0;
}

Save and Compile the Code

Save the changes to the grade.cpp file and exit the editor. To compile the code, run the following command in the terminal:

g++ ~/project/grade.cpp -o grade && ./grade

The above command will compile the code and create an executable file named grade. The ./grade command is used to run the executable file and execute it.

Test the Program

If everything is done correctly, you will see the following output in the terminal:

Enter score(0-100):

Type in a score and press enter, and you should see an output similar to the following:

Grade = A

Summary

In this lab, we created a C++ program to find the grade based on the score using the switch case statement. We learned how to take input from the end-user and then effectively use the switch case statement to calculate the corresponding grade.