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Create a class with two constructors in C++

By IncludeHelp Last updated : November 04, 2023

In C++, a class may have more than one constructor function with different parameter lists with respect to the number and types of arguments. The concept of multiple constructors in a class is known as Constructor overloading.

Problem statement

Write a C++ program to create a class with two constructors.

Algorithm

• Define a class with some data members.
• Create two constructors. In the below example, we are defining two constructors one is without parameters and the second one is with the parameters.
• Create member functions to perform operations on the data members.
• Inside the main function, create objects by passing the different number of arguments to test the functionality of the concept of constructor overloading.

Example

Consider the below example to create a class with two constructors in C++.

#include <iostream>
using namespace std;

// defining class
class Student {
 private:
  // data members
  int english, math, science;

 public:
  // constructor without parameters
  Student() { english = math = science = 0; }

  // constructor with parameters
  Student(int english, int math, int science) {
    this->english = english;
    this->math = math;
    this->science = science;
  }

  // member functions

  // To display values
  void getValues() {
    cout << "English marks: " << english << endl;
    cout << "Math marks: " << math << endl;
    cout << "Science marks: " << science << endl;
  }
  // To return total marks
  int getTotalMarks() { return english + math + science; }

  // To return total marks
  float getPercentage() { return ((float)getTotalMarks() / 300 * 100); }
};

int main() {
  // Create objects
  Student std1;
  Student std2(65, 90, 92);

  // Display the values, calculate and display the
  // total marks and Percentage
  cout << "std1..." << endl;
  std1.getValues();
  cout << "Total marks: " << std1.getTotalMarks() << endl;
  cout << "Percentage: " << std1.getPercentage() << endl;
  cout << endl;

  cout << "std2..." << endl;
  std2.getValues();
  cout << "Total marks: " << std2.getTotalMarks() << endl;
  cout << "Percentage: " << std2.getPercentage() << endl;
  cout << endl;

  return 0;
}

Output

std1...
English marks: 0
Math marks: 0
Science marks: 0
Total marks: 0
Percentage: 0

std2...
English marks: 65
Math marks: 90
Science marks: 92
Total marks: 247
Percentage: 82.3333