Question

Class Average

Create a program that dynamically creates an array whose size depends on the user's preference. Pass the array to a calculate_avg function that is responsible for computing the average GPA of the given array. Use pointer arithmetic throughout your program.

calculate_avg

Create a function called calculate_avg that calculates the average of a double array and returns that average.

calculate_avg() will have two parameters:

1. a double* referring to the array
2. an int that contains the size of the given array.

When the array is size is greater than 0, the function should calculate the average GPA from the given array of grades.

However, when the size of the array is 0, then the function should return 0.

main

The main function has mostly been built for you. It is your task to dynamically create a double array, store users' grades into the array, and pass the array to calculate_avg to compute and then display the students' average GPA. Read the instructions in main.cpp for more details.

If the user happens to provide a class size of 0, then the program should output "You have no class!" and then end the execution of the program without attempting to calculate the average.

Do not forget to deallocate memory that your code dynamically created.

Place the calculate_avg's function prototype in calculate_avg.hpp and it's implementation in calculate_avg.cpp.

Sample Output

How many students are in your class? 5
Enter the GPA for the students in your class (0.0 - 4.0)
Enter the GPA for student #1: 3.8
Enter the GPA for student #2: 2.5
Enter the GPA for student #3: 4.0
Enter the GPA for student #4: 1.9
Enter the GPA for student #5: 3.6
Class average: 3.16

How many students are in your class? 0
You have no class!

c++

Answer 1

Executable Code:



calculate_avg.hpp

#include <iostream>

#include <iomanip>

using namespace std;

double calculate_avg(double *, int);

calculate_avg.cpp

#include "calculate_avg.hpp"

double calculate_avg(double *grades, int n)

{

double sum = 0;

for(int i = 0; i < n; i++)

{

sum += *(grades + i);

}

return (sum / n);

}

main.cpp

#include "calculate_avg.hpp"

int main()

{

int n;

cout << "How many students are in your class? ";

cin >> n;

if(n <= 0)

{

cout << "You have no class!" << endl;

exit(0);

}

double grades[n];

cout << "Enter the GPA for the students in your class (0.0 - 4.0)" << endl;

for(int i = 0; i < n; i++)

{

double inp;

cout << "Enter the GPA for the student #" << (i + 1) << ": ";

cin >> inp;

while(inp < 0.0 || inp > 4.0)

{

cout << "GPA must be between 0.0 - 4.0!\n\n";

cout << "Enter the GPA for the student #" << (i + 1) << ": ";

cin >> inp;

}

grades[i] = inp;

}

double average = calculate_avg(grades, n);

cout << setprecision(2) << fixed << "Class average: " << average << endl;

return 0;

}

Sample Output: