C++ Program to Calculate the grade of the student using a user-defined function

Here, we are discussing a program to find the Grade of a Student based on Marks obtained in all Subjects using a user-defined function. Here the user is allowed to enter the number of subjects
The grade must be calculated based on the following pattern:
Average Mark Range    Grade
91-100    A1
81-90    A2
71-80    B1
61-70    B2
51-60    C1
41-50    C2
33-40    D
21-32    E1
0-20    E2

How do calculate the grade of a student?

To calculate the grade of a student based on total marks. The grade is calculated based on the total marks obtained for n subjects. Add marks of all the n subjects and divide it by n to get the average mark. And based on this average mark, find the grade as per the table given above:

C++ program to calculate the grade of a student

Here the program asks the user to enter the number of the subject. For example, if he/she enters 3 as the number of subjects, then the program further asks to enter marks obtained in 3 subjects.
This program calculates the grade of the student using a user-defined function
Get the number of subjects into the variable n and get the marks of n subjects to the array mark[10]; pass the array of marks and the number of subjects to a user-defined function that says findGrade( float mark[ ], int n );
Defining the function findGrade (float [ ], int)
First, we have to add all the marks for n subjects. For this, get each subject’s mark and add them together.


float sum=0;
for(i=0; i


Now we have to divide the total mark by the number of subjects to get the average.
avg = sum/n;
Now we have the average mark in the variable avg. Compare the value with the average mark range.



if(avg>=91 && avg<=100)

        return "A1";

    else if(avg>=81 && avg<91)

        return "A2";

    else if(avg>=71 && avg<81)

        return "B1";

    else if(avg>=61 && avg<71)

        return "B2";

    else if(avg>=51 && avg<61)

        return "C1";

    else if(avg>=41 && avg<51)

        return "C2";

    else if(avg>=33 && avg<41)

        return "D";

    else if(avg>=21 && avg<33)

        return "E1";

    else if(avg>=0 && avg<21)

        return "E2";

    else

        return "Invalid!"

get the return value of the function and display the grade.


Algorithm

Step 1: Call the header file iostream.

Step 2: Use the namespace std.

Step 3: Declare a user defined function const char* findGrade(float [], int);

Step 4: Open the integer type main function; int main().

Step 5: Declare integer type variables I, n. float type array mark[10];

Step 6: Ask the user to enter the number of subjects

Step 7:Get the number into the variable n;

Step 8: Ask the user to enter the marks obtained;

Step 9: Get the numbers into the array mark[10];

Step 10: call step: 13 and get the grade 

Step 11:Print the grade; 

Step 12: exit;

Step 13: const char* findGrade(float mark[], int n)
              Calculate the total marks and get the result into a variable sum;
              Calculate the average and get the result into the variable avg;
              Compare the value of avg with the average mark range and return the                                 corresponding grade;


 

C++ Source Code

                                          #include<iostream>
using namespace std;
const char* findGrade(float [], int);
int main()
{
    int i, n;
    float mark[10];
    cout<<"Enter Number of Subjects (max. 10): ";
    cin>>n;
    cout<<"Enter Marks obtained in "<<n<<" Subjects: ";
    for(i=0; i<n; i++)
        cin>>mark[i];
    cout<<"\nGrade = "<<findGrade(mark, n);
    cout<<endl;
    return 0;
}
const char* findGrade(float mark[], int n)
{
    int i;
    float sum=0, avg;
    for(i=0; i<n; i++)
        sum = sum+mark[i];
    avg = sum/n;
    if(avg>=91 && avg<=100)
        return "A1";
    else if(avg>=81 && avg<91)
        return "A2";
    else if(avg>=71 && avg<81)
        return "B1";
    else if(avg>=61 && avg<71)
        return "B2";
    else if(avg>=51 && avg<61)
        return "C1";
    else if(avg>=41 && avg<51)
        return "C2";
    else if(avg>=33 && avg<41)
        return "D";
    else if(avg>=21 && avg<33)
        return "E1";
    else if(avg>=0 && avg<21)
        return "E2";
    else
        return "Invalid!";
}
                                      

OUTPUT

Enter Number of Subjects (max. 10): 6
Enter Marks obtained in 6 Subjects: 69
80
55
74
45
91
Grade = B2