Passing array of objects as parameter in C++

Array of Objects:It is an array whose elements are of the class type. It can be declared as an array of any datatype.

Syntax:

classname array_name [size];

Below is the C++ program to illustrate the array of objects by calculating the highest marks among 3 students:

C++

// C++ program to illustrate the
// passing the array of objects
// to function parameter
#include <bits/stdc++.h>
using namespace std;

// Class Student
class Student {
    int roll;
    char name[50];
    int total;

public:
    // Function to input Roll Number
    void getdata()
    {
        cout << "Enter your Roll: "
             << endl;
        cin >> roll;
        cout << "Enter your Name: "
             << endl;
        cin.ignore();
        cin.get(name, 50);
        cout << "Enter your Total "
             << "Marks: " << endl;
        cin >> total;
    }

    // Function to pass the array of
    // objects
    int pos(Student obj[], int size)
    {
        int pos = 0;
        int max = obj[0].total;

        // Traverse the array of object
        for (int i = 0; i < size; i++) {
            if (obj[i].total > max) {
                max = obj[i].total;
                pos = i;
            }
        }
        return pos;
    }

    // Function to display the students
    // details
    void putdata()
    {
        cout << "Roll: " << roll
             << endl;
        cout << "Name: " << name
             << endl;
        cout << "Total Marks: "
             << total << endl;
    }
};

// Function that have array of objects
void arrayOfObjects()
{
    Student s[3], s1;
    int pos;
    for (int i = 0; i < 3; i++) {
        s[i].getdata();
    }
    pos = s1.pos(s, 3);
    cout << "Highest scoring Student"
         << " Details:" << endl;
    s[pos].putdata();
}

// Driver Code
int main()
{
    // Function Call
    arrayOfObjects();

    return 0;
}

Output:

Explanation:

• In the main() function, objects of the Student class are created:
  • Here, the first array of objects is s[3] and the other one is s1(a simple object).
  • In the for loop, 3 sets of user input have been taken, (i.e, it is where the user will be entering the name, roll, total marks, for 3 students sets).
  • Then passing the s[3] (array of an object which contains the sets of student details) and its size, through the s1 object in the pos(Student obj [], int size) member function.
• The pos(Student obj [], int size) function, is returning the position of the object of the highest total marks scoring student set, i.e, (0, 1or 2 index position of s[3] object array), which is stored in pos = s1.pos(s, 3).
• Display part: For calling the display function, S[pos].putdata() is used.
  • The putdata() function is displaying the object details of the student class.
  • Here, pos is sent (which stores the index position of the highest student set object) in s, to display the highest total marks scored student details.

Time Complexity: O(n)
Auxiliary Space: O(n)