Real Time Scenerio for abstract class and interface

[Giri moh'kar]

when do we use abstract class and interface?do we have any real time example?

[Peter Chase]

I'm guessing you don't really mean real time.

[Kaydell Leavitt]

Welcome to the Java Ranch,

I take it that you mean "real-world" instead of "real-time".

A real-world example is a "fruit". We can consider using either an interface or an abstract class. Since all fruits have a common property, weight, an abstract class should be used rather than an interface since interfaces can't contain variables. (Though, you might find a reason to use both an abstract class and interfaces).

Concrete classes of fruit could be "apple", "bannanna", and a "pear".

abstract class Fruit {

    private double weight;
    
    public Fruit(double weight) {
         this.weight = weight;
    }
    
    public double getWeight() {
    return weight;
    }
    
    @Override
    public String toString() {
    return "Fruit";
    }
}
 
class Apple extends Fruit {
    public Apple(double weight) {
        super(weight);
    }
    @Override
    public String toString() {
    return "Apple";
    }
}
 
public class RealWorldAbstractClass {

 public static void main(String[] args) {
Apple a = new Apple(0.5);
Fruit f = new Apple(0.6);
System.out.println("a is really an " + a.toString() + " it weighs " + a.getWeight());
System.out.println("f is really an " + f.toString() + " it weighs " + f.getWeight());
}
 
}

Kaydell
[ June 11, 2007: Message edited by: Kaydell Leavitt ]

[Giri moh'kar]

Thanks Kaydell Leavitt..