java assignment

public class Activity1B { public static void main(String[] args) { Item[] inventory = new Item[4]; inventory[0] = new Item("machine bolt", 50, "M50-H", 120); inventory[1] = new Item("phillips screw", 25, "P25-16", 750); inventory[2] = new Item("lock washer", 12, "W12-L", 400); inventory[3] = new Item("drywall screw", 38, "P38-DW", 2400); printInventory(inventory); sell(inventory[0], 90); sell(inventory[1], 750); sell(inventory[2], 600); sell(inventory[3], 2500); printInventory(inventory); inventory[0].order(90); inventory[1].order(1); inventory[2].order(220); inventory[3].order(50); printInventory(inventory); System.out.println("\nEnd of processing."); } public static void sell(Item item, int amount) { int inStock; inStock = item.sell(amount); System.out.print("Selling " + amount + " of item: "); if (inStock == amount) { System.out.println("all are in stock."); } else { System.out.println(inStock + " in stock, " + (amount - inStock) + " on backorder."); } } public static void printInventory(Item[] inventory) { System.out.println("Inventory:"); for (int i = 0; i < inventory.length; i++) { System.out.println(inventory[i]); } } } class Item { private String name; private int size; private String code; private int quantity; public Item(String name, int size, String code, int quantity) { this.name = name; this.size = size; this.code = code; this.quantity = quantity; } public int sell(int amount) { int result = amount; if (amount > quantity) { result = quantity; } quantity -= amount; return result; } public void order(int amount) { quantity += amount; } public String toString() { String result; result = "Item '" + name + "' size=" + size + "mm code='" + code; if (quantity >= 0) { result += " quantity=" + quantity; } else { result += " quantity=0 (" + -quantity + " backordered)"; } return result; } }