Question: Explain the difference between a class and an object in the context of object-oriented programming. Provide an example of a class and an object in Java and explain how they are related.

Answer:

A class is a blueprint or template for creating objects in object-oriented programming. It defines the properties and behaviors that objects of that class will have. On the other hand, an object is an instance of a class, and it represents a specific entity in a program.

Example of a class in Java:

public class Car {
    String make;
    String model;
    int year;

    public void startEngine() {
        System.out.println("Engine started");
    }

    public void stopEngine() {
        System.out.println("Engine stopped");
    }
}

Explanation of the class example: In the example above, we have defined a class called "Car" with properties such as make, model, and year, as well as behaviors like starting and stopping the engine.

Example of an object in Java:

public class Main {
    public static void main(String[] args) {
        Car myCar = new Car();
        myCar.make = "Toyota";
        myCar.model = "Corolla";
        myCar.year = 2020;

        myCar.startEngine();
    }
}

Explanation of the object example: In the Main class, we create an object of the Car class called "myCar" using the new keyword. We then set the properties of the object using dot notation and execute the startEngine method on the myCar object.

In this example, the class Car serves as the template for creating objects that represent individual cars, while the object "myCar" is an instance of the Car class with specific properties and behaviors.

The relationship between a class and an object is that a class defines the structure and behavior of objects, while an object is a concrete instance of that class, representing a specific entity or concept within a program.