Java Inner class demo program
An inner class is a class inside another class. The main purpose of using an inner class is to group related classes together.
Java program
import java.text.DecimalFormat; public class Item { private String description; // description private int itemNumber; // number private Cost cost; // Cost /** * Item constructor **/ public Item(String desc, int itemNum, double wholesale, double retail) { description = desc; itemNumber = itemNum; cost = new Cost(wholesale, retail); } /** * RetailItem class toString method */ public String toString() { String str; DecimalFormat dollar = new DecimalFormat("#,##0.00"); str = "Description: " + description + "\nItem Number: " + itemNumber + "\nWholesale Cost: $" + dollar.format(cost.getWholesale()) + "\nRetail Price: $" + dollar.format(cost.getRetail()); return str; } /** * Inner Class */ private class Cost { public double wholesalePrice; public double retailsalePrice; public double getWholesale() { return wholesalePrice; } public void setWholesale(double wholesale) { this.wholesalePrice = wholesale; } public double getRetail() { return retailsalePrice; } public void setRetail(double retail) { this.retailsalePrice = retail; } /** * Cost constructor */ public Cost(double w, double r) { wholesalePrice = w; retailsalePrice = r; } } }
Test Driver
/** * Item class */ public class InnerClassDemo { public static void main(String[] args) { Item item = new Item("Rice Packet", 1001,1.75, 2.50); System.out.println(item); } }