JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech III OBJECT ORIENTED PROGRAMMING THROUGH JAVA Previous Question Paper (August - 2022 - R18)

The object-oriented paradigm was developed to overcome the limitations of procedural programming, specifically regarding code complexity, maintenance, and scalability. As software systems grew in size, procedural approaches led to "spaghetti code" where data and functions were loosely coupled, making debugging and modification difficult.

Key reasons for the need for the object-oriented paradigm include:

• Encapsulation: It binds data and the methods that operate on that data into a single unit (class), protecting the internal state from unauthorized access.
• Reusability: Through inheritance, existing code can be extended or reused in new classes, reducing redundancy and development time.
• Maintainability: Modular design allows developers to update or fix specific components without affecting the entire system.
• Abstraction: It allows developers to hide complex implementation details and expose only the necessary functionality, simplifying the interaction with objects.
• Polymorphism: It provides the ability for objects to take on multiple forms, allowing a single interface to represent different underlying types, which enhances flexibility in system design.

Constructor overloading in Java allows a class to have multiple constructors with different parameter lists. The compiler distinguishes between them based on the number and type of arguments passed during object creation.

class Student {
    String name;
    int age;

    // Constructor with no arguments
    Student() {
        name = "Unknown";
        age = 0;
    }

    // Constructor with one argument
    Student(String n) {
        name = n;
    }

    // Constructor with two arguments
    Student(String n, int a) {
        name = n;
        age = a;
    }

    void display() {
        System.out.println("Name: " + name + ", Age: " + age);
    }
}

public class ConstructorDemo {
    public static void main(String[] args) {
        Student s1 = new Student();
        Student s2 = new Student("Alice");
        Student s3 = new Student("Bob", 20);

        s1.display();
        s2.display();
        s3.display();
    }
}