What is a class and an object in Java?

Question

Ravi Vishwakarma · Answer

Class

A class in Java is a blueprint or template for creating objects. It defines the properties (fields) and behaviors (methods) that the objects created from the class will have.

Fields (Instance Variables): Attributes or properties that define the state of the objects.
Methods: Functions that define the behaviors or actions that the objects can perform.
Constructors: Special methods used to initialize new objects.

Example:

public class Car {
    private String color;
    private String model;
    private int year;

    public Car(String color, String model, int year) {
        this.color = color;
        this.model = model;
        this.year = year;
    }

    public void displayDetails() {
        System.out.println("Car Model: " + model + ", Year: " + year + ", Color: " + color);
    }
}

Object

An object is an instance of a class. It represents a specific entity with a state defined by the fields and behaviors defined by the methods of the class.

State: The data held in the object's fields.
Behavior: The methods that can be called on the object.

Example:

public class Main {
    public static void main(String[] args) {
        Car myCar = new Car("Red", "Toyota Camry", 2021);
        myCar.displayDetails(); // Output: Car Model: Toyota Camry, Year: 2021, Color: Red
    }
}

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What is a class and an object in Java?

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1 Answers

Class

Object