Java contoh kelas

// instanceof can be used to check whether an object
// is an instance of a given class or not, as illustrated below
public class Main {
	public static void main(String[] args) {
		String str = new String("Foo");
		System.out.println( str instanceof String); // true
		Shape s = new Triangle();
      	// s is instance of parent class Shape
		System.out.println(s instanceof Shape); // true
      	// s is also instance of child class called Triangle
		System.out.println(s instanceof Triangle); // true

	}
}
class Shape {
	public void draw() {
		System.out.println("Shape draw.");
	}
}
class Triangle extends Shape {
	public void draw() {
		System.out.println("Triangle draw.");
	}
}
Wissam