CHASH Tutorial

Constructors and Destructors in C++

In C++, constructors and destructors are special member functions of a class that are automatically called when an object is created or destroyed.

🔧 Constructor Characteristics:

• Same name as the class.
• No return type (not even void).
• Can be overloaded (multiple constructors).

🔧 Destructor Characteristics:

• Same name as the class, but with a ~ (tilde) before it.
• No return type and no parameters.
• Cannot be overloaded — only one destructor per class.

📄 Example: Constructor and Destructor

#include <iostream>
using namespace std;

class Student {
  public:
    Student() {
      cout << "Constructor called!" << endl;
    }

    ~Student() {
      cout << "Destructor called!" << endl;
    }
};

int main() {
  Student s1;
  return 0;
}
  

🖨️ Output:

🔍 Explanation:

• When s1 is created, the constructor is automatically invoked.
• At the end of main(), the destructor is automatically invoked.

🧠 Constructor Overloading

class Student {
  public:
    Student() {
      cout << "Default Constructor" << endl;
    }

    Student(string name) {
      cout << "Parameterized Constructor: " << name << endl;
    }
};

Student s1;            // Calls default constructor
Student s2("Rahul");   // Calls parameterized constructor
  

🎓 Summary

• Constructor initializes objects when created.
• Destructor cleans up memory or resources when objects are destroyed.
• Both help in proper management of object lifecycle in C++.