how to write class with data members and member function c++ - visual-c++

Question

hi guys i would like u to help me in my assignment i had try to solve it but there are some of the things that making me :s i knw how to creat the name and id
string Name;
int Id;
bt wt does it mean a pointer to a dynamically allocated array of grades:s:s:S?
i jst knw how to declare a pointer like : double* Grades;
here is the assignment......
Create a Class StudentGrades with the following Data members:
Name : type String
Id: type integer
Grades: a pointer to a dynamically allocated array of Grades. Type is: pointer to double (* double)
It includes the following member functions:
A No-argument Constructor
A Constructor that takes two arguments : a String and an Integer and initializes the Name with the String and the ID with the Integer.
Set and get functions for Name, ID
A print function for Student information. It prints name, Id and the grades.
An overloaded Assignment operator of the Class Objects
A Copy Constructor of the Class Objects
Use the Syntax for the copy constructor and the overloaded assignment operator.
In another file create a C++ program that prompts the user for data to create four objects of the class StudentGrades. The first object (std1) has 5 grades, and the second (std2) has 6 grades and the third (std3) has 4 grades and fourth (std4) has no grades and data.
Then copy std2 into std4 and assign std1 to std3. Then print the details of the four objects
hey i solved my assignment bt iam trying to running it bt it doesn't work can any body please tell me where the problem is n the program
#include <iostream>
using namespace std;
class student_grades{
private:
string name,n;
int Id,i;
double* grades[];
public:
student_grades();
student_grades(sting, int);
student_grades(const student_grades&);
void set(string name,int Id){
cout << "enter the name and the ID";
cin >> n >> i;
n = name;
i = Id;
}
void get(){
return i;
return n;
}
void student_grades (student_grades&opr){
name = name.opr;
Id = Id.opr;
grades[] = grades[].opr;
}
void student_info(){
cout << "the name of the student is:" << name;
cout << "the id for the srudent is:" << Id;
grades = new double[];
cout << "the grades of the student is:" << grades[] << endl;
delete []grades;
}
};
student_grades::student_grades() {}
student_grades::student_grades(string name, int Id) {
name=" ";
Id=0;
}
student_grades::student_grades(const student_grades& copy) {
name=copy.name;
Id=copy.Id;
}
int main() {
student_grades std1;
std1.set();
cin >> std1.grades[5];
std1.get();
student_grades std2;
std2.set();
cin >> std2.grades[6];
std2.get();
student_grades std3;
std3.set();
cin >> std3.grades[4];
std3.get();
student_grades std4;
std4.set();
cin >> std4.grades[];
std4.get();
std1 = std3;
std2 = std4;
cout << std1 << std2 << std3 << std4;
return 0;
}

Answer 1

A dynamically allocated array is an array that isn't given a specific size until run time, unlike a fixed array declaration is at compile time. A declaration of a fixed array looks like:
int grades[500];
That array will allocate memory for 500 integers and stay that way unless you destroy it or resize it.
Creating a dynamically allocated array would look more like this:
int* grades = NULL; // A declaration in your StudentGrades class
int n = <get size from somewhere>; // Makes the size "dynamic"
grades = new int[n]; // This definition could be in your StudentGrades ctor,
// with n being a parameter.
Then you could continue by initializing all of the array elements to 0 or fill up your array with other values as needed. When you're done with the array, clean it up. This could be in your destructor:
delete [] grades;
grades = NULL;