object in java

An object in Java is an instance of a class. It is a runtime entity that represents a real-world entity, concept, or thing. Objects have properties (attributes) and behaviors (methods) defined by their class.

Here are some key characteristics of objects:

• 1. Instantiation: Objects are created using the new keyword followed by the class name and optional constructor arguments. This process is called instantiation.
• 2. State: Each object has its own state, which is determined by the values of its instance variables. These variables define the properties or attributes of the object.
• 3. Behavior: Objects can perform actions or behaviors defined by their methods. These methods encapsulate the functionality associated with the object.
• 4. Identity: Each object has a unique identity within the JVM. Even if two objects have the same state, they are distinct entities with different identities.
• 5. Reference: Objects are accessed and manipulated through references. A reference is a variable that holds the memory address (reference) of an object.
• 6. Passing Objects: Objects can be passed as arguments to methods and returned from methods. When an object is passed, its reference is passed, allowing the method to access and modify the object’s state.
• 7. Garbage Collection: Java uses automatic garbage collection to reclaim memory occupied by objects that are no longer referenced. When no references to an object exist, it becomes eligible for garbage collection.

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

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

    public void drive() {
        System.out.println("Driving the " + year + " " + make + " " + model);
    }
}

public class Main {
    public static void main(String[] args) {
        // Creating an object of the Car class
        Car myCar = new Car("Toyota", "Corolla", 2022);

        // Accessing object properties and calling methods
        System.out.println("Make: " + myCar.make);
        System.out.println("Model: " + myCar.model);
        System.out.println("Year: " + myCar.year);
        myCar.drive();  // Calling the drive method
    }
}

In this example, ‘myCar’ is an object of the Car class. It has properties (‘make’, ‘model’, ‘year’) and a behavior (‘drive’ method) defined by the class. The object is instantiated using the ‘new’ keyword, and its properties are accessed and methods are called using the object reference (‘myCar’).