The Difference Between Class and Object in Java

In Java programming, understanding the distinction between 'class' and 'object' is essential. While they are related concepts, each serves a distinct purpose in object-oriented programming.

What is a Class?

A class in Java is a blueprint or template that defines the structure and behavior of objects. It contains attributes (fields) and methods that define the object's state and behavior. Here's a simplified definition:

"A class is a static piece of code that defines the attributes and methods shared by all instances (objects) of that class."

What is an Object?

An object is an instance of a class. It represents a specific entity that exists at runtime and has its own state (attributes) and behavior (methods). Unlike classes, objects are dynamic and exist only during the program's execution:

"An object is a specific instance of a class, created at runtime with its own set of attributes and methods."

Example: Class vs. Object

Consider a class Animal with attributes like species and age:

public class Animal {
    String species;
    int age;

    public Animal(String species, int age) {
        this.species = species;
        this.age = age;
    }

    public void eat() {
        System.out.println("The animal is eating.");
    }
}

Creating objects of the Animal class:

Animal lion = new Animal("Lion", 5);
Animal cat = new Animal("Cat", 2);

Key Differences:

• Class: Defines the structure and behavior shared by all instances.
• Object: Represents a specific instance with its unique state and behavior.

Conclusion

Understanding the distinction between class and object is fundamental in Java programming. Classes provide the blueprint, while objects are the tangible instances that embody those blueprints.