Constructor in Java 🚀

By Bhau Automation • Java OOPs Tutorial for Beginners

🎯 What You Will Learn

• What is a constructor in Java?
• Purpose of constructor
• Types of constructors
• Java constructor examples
• Java interview questions on constructors

💡 Constructors are one of the most important OOPs concepts in Java and are widely used in real-world applications.

📌 What is a Constructor in Java?

A constructor in Java is a special method used to initialize objects. It is automatically called when an object is created.

Important points about constructors:

• Constructor name must be same as class name
• Constructors do not have return type
• Called automatically during object creation
• Used to initialize variables

⚙️ Purpose of Constructor

Constructors are mainly used for:

• Initializing object data
• Reducing repetitive code
• Assigning default values
• Improving code readability

🛠️ Syntax of Constructor

class Student {

    Student() {

        System.out.println("Constructor Called");
    }
}

💻 Default Constructor Example

class Employee {

    Employee() {

        System.out.println("Default Constructor");
    }

    public static void main(String[] args) {

        Employee e = new Employee();
    }
}

💻 Parameterized Constructor Example

class Student {

    int id;
    String name;

    Student(int i, String n) {

        id = i;
        name = n;
    }

    void display() {

        System.out.println(id + " " + name);
    }

    public static void main(String[] args) {

        Student s1 = new Student(101, "Rahul");

        s1.display();
    }
}

📚 Types of Constructors in Java

• Default Constructor
• Parameterized Constructor
• Copy Constructor (custom implementation)

🔥 Rules of Constructors

• Constructor cannot be static
• Constructor cannot be abstract
• Constructor can be overloaded
• Constructor executes only once per object creation

🌍 Real-World Use Cases

• Banking applications
• Student management systems
• Automation frameworks
• Spring Boot applications

❓ Common Interview Questions

🎥 Watch Complete Video Tutorial

👉 Watch Constructor in Java Tutorial

🎓 Key Takeaways

• Constructors initialize objects in Java
• Constructors are automatically called
• Parameterized constructors help assign custom values
• Constructor overloading improves flexibility
• Important Java interview topic

⚡ Pro Tip: Practice constructor programs daily to build strong understanding of object creation and OOPs concepts.

🚀 Created with ❤️ by Bhau Automation