get average grade for 10 students c++ - c++

Question

This program will need to handle all grades for 10 students.
Each student has a first and last name, an id number,
3 homework grades, 3 labs grades, 3 test grades, and 1 final exam grade.
display the final course grade in both numbered and letter version
The equation only works for the first set of grades then it adds a little bit to the next average I just can't figure out whats wrong.
/*This program will need to handle all grades for 10 students.
Each student has a first and last name, an id number,
3 homework grades, 3 labs grades, 3 test grades, and 1 final exam grade.
display the final course grade in both numbered and letter version
*/
#include <iostream> // main library
#include <string> //enables use of strings
#include <iomanip> // for setw
#include <Windows.h> // used to set console title
using namespace std; // for cout and cin
const int MAXSTUDENTS = 2;
const int MAXGRADES = 3;
const int MINGRADES = 1;
int main()
{// Get names form students
SetConsoleTitle("Gradebook");
double hwGrade[MAXSTUDENTS][MAXGRADES];
double labGrade[MAXSTUDENTS][MAXGRADES];
double testGrade[MAXSTUDENTS][MAXGRADES];
double feGrade[MAXSTUDENTS];
double final_num_grade[MAXSTUDENTS];
double hwAve =0, labAve=0, testAve=0; // this will be used to calculate the averages
string fName[MAXSTUDENTS];
string lName[MAXSTUDENTS];
string line; // to set the two string variables
string id[MAXSTUDENTS]; // id will be a whole number so int was apropiate
//first for statement. ensuere that the program is run 10 times
for (int s = 0; s < MAXSTUDENTS; s++) {
cout << "Enter student's first name: "; // ask the user for the first name
getline(cin, fName[s]); // accepts students first name
cout << "Enter stedent's last name: "; //ask the user for last name
getline(cin, lName[s]); // accepts students last name
cout << "Enter student's id: "; // ask user for student id
getline(cin, id[s]);
// this loop will ask for three homework grades
for (int n = 0; n < MAXGRADES; n++) {
cout << "Homework grade " << n + 1 << " is "; //tells the user waht the program needs
cin >> hwGrade[s][n]; //lets the user input the homework grades
hwAve += hwGrade[s][n];
}
hwAve = hwAve / 3;
// this loop will ask for three lab grades
for (int l = 0; l < MAXGRADES; l++) {
cout << "Lab grade " << l + 1 << " is ";
cin >> labGrade[s][l]; //lets the user input the LAB grades
labAve += labGrade[s][l];
}
labAve = labAve / 3;
//this loop will ask for three test grades
for (int t = 0; t < MAXGRADES; t++) {
cout << "Test grade " << t + 1 << " is ";
cin >> testGrade[s][t]; //lets the user input the test grades
testAve += testGrade[s][t]; // the average is calculated
}
testAve = testAve / 3;
cout << "Final exam grade: "; // asks user for final exam grade
cin >> feGrade[s];
// equation to get the final course grade
final_num_grade[s] = (hwAve * 0.20) + (labAve * 0.25) + (testAve * 0.30) + (feGrade[s] * 0.25);
line.assign(50, '-');
cout << line << endl;
}
for (int i = 0; i < MAXSTUDENTS; i++) {
cout << "Final Course Grade for " << fName[i] << " " << lName[i] << " with the id " << id[i] << " is " // displays name of student
<< showpoint << fixed << setprecision(1) << final_num_grade[i]; //set to 1 decimal place
//if statement shows the letter grade
if (final_num_grade[i] >= 89.5) { //A if student made 89.5 or more
cout << " (A)\n";
}
else if (final_num_grade[i] >= 79.5) { //B if student made 79.5 to 89.4
cout << " (B)\n";
}
else if (final_num_grade[i] >= 69.5) { // C if student made 69.5 yo 79.4
cout << " (C)\n";
}
else if (final_num_grade[i] >= 59.5) { // D if student made 59.5 to 69.4
cout << " (D)\n";
}
else { // F if student made less than 59.4
cout << " (F)\n";
}
}
return 0;
}

Answer 1

You haven't reset these variables to zero : hwAve, labAve, testAve which makes the second student's grade will be slightly higher