Building with Objects: The Heart of Java

Java is an object-oriented language, which means you organize your code around real-world things called objects. Each object comes from a class, which is like a blueprint.

Defining a Class

A class defines the properties (fields) and behaviors (methods) of an object.

public class Dog {
  String name;
  int age;
  
  void bark() {
    System.out.println(name + " says woof!");
  }
}

Creating Objects

Dog myDog = new Dog();
myDog.name = "Buddy";
myDog.age = 3;
myDog.bark(); // Output: Buddy says woof!

Why Use OOP?

• Organize code to match real-world ideas.
• Make programs easier to build and understand.
• Reuse code by creating multiple objects from the same class.

Real-World Examples

• A Car class for a racing game, each with different colors and speeds.
• A Student class for a school system, tracking names, grades, and ID numbers.