Printing error with constant

[hamzams25]

Write your question here.

  I'm doing this assignment for my class. I have gotten the program to ork but I am having an issue.
When the program prints itself. It prints the information that is given in the array and then prints the random values for the constants. 
For example if i input the value for 1 student and the constant is 30. It will print the value for the first student as it is supposed to, but then it will also print the next 29 students with random information.

#include <cstdlib>
#include <iostream>
#include "student.h"
#include <string>
using namespace std;

const int MAX_STUDENT=30;
typedef Student studentArrayType[MAX_STUDENT];
void printMeFirst();



int main(int argc, char** argv) 

{

printMeFirst();

Student s1;
Person teacher;
studentArrayType studentArray;

string grade;
string dummy; 


teacher.firstName = "Ron"; 
teacher.lastName = "Sha";

cout << "CS116: " << teacher.firstName << " " << teacher.lastName << endl;



for (int i = 0; i < MAX_STUDENT; i++)
{
cout << "Enter First name (enter Q if no more inputs): ";
cin >> studentArray[i].name.firstName;
if (studentArray[i].name.firstName == "Q")
break;

cout << "Enter Last name (enter Q if no more inputs): ";
cin >> studentArray[i].name.lastName;

cout << "Enter bird year: ";
cin >> studentArray[i].birthYear;

cout << "Enter birth month: ";
cin >> studentArray[i].birthMonth;

cout << "Enter birth day: ";
cin >> studentArray[i].birthDay;

cout << "Enter percent: ";
cin >> studentArray[i].courseGrade.percent;


} 
// try to omit this line when compiling, see the difference
// if you enter multiple words as inputs
// get rid of cin buffer
//getline(cin, dummy);
cin.clear();
cin.ignore(30, '\n');


//fix print letter for number


calculateGrade(studentArray, MAX_STUDENT); 

cout << "Student Info: \n\n";
printStudent(studentArray, MAX_STUDENT);

return 0;
}


void calculateGrade(Student studentArray[], int size)
{
// loop the entire student array and assign leter grade
// as below: (last element of the array is either the end
// of the array, or the student's first name is "Q"
//
// Letter grade based on grade percent: 
// A: 89 and above
// B: 79 and above and less than 89
// C: 69 and above and less than 79
// D: 59 and above and less than 69
// F: below 59 

// your code below

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

{
if (studentArray[i].courseGrade.percent >= 89)
{
studentArray[i].courseGrade.grade = "A";
}
else if (studentArray[i].courseGrade.percent >= 79 && studentArray[i].courseGrade.percent < 89)
{
studentArray[i].courseGrade.grade = "B";
}
else if (studentArray[i].courseGrade.percent >= 69 && studentArray[i].courseGrade.percent < 79)
{
studentArray[i].courseGrade.grade = "C";
}
else if (studentArray[i].courseGrade.percent >= 59 && studentArray[i].courseGrade.percent < 69)
{
studentArray[i].courseGrade.grade = "D";
}
else if (studentArray[i].courseGrade.percent < 59)
{
studentArray[i].courseGrade.grade = "F";
}
}
}


/*
* Function: printStudent
* print out all the student's information
* 
* @studentArray: the array contains all the student's info
* @size: size of the studentArray
* 
* Output:
* print all all the student's info
* Return: none
* 
*/

void printStudent(Student studentArray[], int size)
{
/*
* print out all the student's infor:
* First name, last name, birthday (month/day/year), 
* course percent and course letter grade
* 
* Last element of the array is the end of the array or student's
* first name is "Q"
*/
for (int i=0; i < size; i++)

{
cout << studentArray[i].name.firstName << " is my first name." << endl;
cout << studentArray[i].name.lastName << " is my last name." << endl;
cout << "I was born on " << studentArray[i].birthDay << "//" << studentArray[i].birthMonth << "//" << studentArray[i].birthYear << endl;
cout << "I got a " << studentArray[i].courseGrade.percent << " percent" << endl;
cout << "I got an " << studentArray[i].courseGrade.grade << endl;
cout << endl << endl;

}

}

//find variable to track how many students are in the array

//The function below will print out the progeammers name, class info, time, and date.
void printMeFirst()
{
cout << "Program written by: " << "Hamza Sheikh" << endl;
cout << "Course info: " << "Lab1: Students" << endl << "CS-116: Thursday class" << endl << endl;
time_t now = time(0);

char* t= ctime(&now);
cout << "Date: " << t << endl << endl;
}

THE ARRAY FILES:
#ifndef STUDENT_H
#define STUDENT_H
#include<string>

using namespace std;

struct Person {
string lastName, firstName;
};

struct GradeRec {
float percent;
string grade;
};

struct Student {
Person name;
int birthYear, birthMonth, birthDay;
GradeRec courseGrade;

};


void calculateGrade(Student studentArray[], int size);
void printStudent(Student studentArray[], int size);

[EricPlusPlus]

In your code you're using MAX_STUDENTS as an argument for some functions with a size parameter. Consequently, some for loops end up doing 30 iterations even though you may only have 1 or 2 students stored in your array because you're passing that value of 30 to those functions via the size parameter. An alternative would be to use a counter and update it every time a student is entered. Then pass to the counter to the functions instead of MAX_STUDENTS.

For example:

if (studentArray[i].name.firstName == "Q")
num_students = i + 1; 
break;

Just before leaving the for loop, assign the value of i + 1 to a variable called num_students. Each time a students info is entered, i is incremented so num_students will reflect that within the scope of main(). Then instead of passing MAX_STUDENTS to your functions, use num_students so you don't do an additional 29 iterations when you only need 1.

calculateGrade(studentArray, num_students);