Question

Please add comments to this code!

Item Class:

import java.text.NumberFormat;
public class Item {

   private String name;
   private double price;
   private int bulkQuantity;
   private double bulkPrice;

   /***
   *
   * @param name
   * @param price
   * @param bulkQuantity
   * @param bulkPrice
   */
   public Item(String name, double price, int bulkQuantity, double bulkPrice) {
       this.name = name;
       this.price = price;
       this.bulkQuantity = bulkQuantity;
       this.bulkPrice = bulkPrice;

   }

   public Item(String name, double price) {
       if (price < 0) {
           throw new IllegalArgumentException();
       }

       this.name = name;
       this.price = price;

   }

   /***
   *
   * @param quantity
   * @return
   */
   public double priceFor(int quantity) {
       double actual = 0;
       if (quantity < 0) {
           throw new IllegalArgumentException();
       } else {
           if (bulkQuantity!=0) {
               actual = (quantity / bulkQuantity) * bulkPrice
                       + (quantity % bulkQuantity) * price;
           } else {
               actual = quantity * price;
           }
       }

       return actual;

   }

   public boolean equals(Item ietm) {
       return this.name.equals(ietm.name);
   }

   @Override
   public String toString() {
       NumberFormat format = (NumberFormat) NumberFormat.getCurrencyInstance();

       format.setMinimumFractionDigits(2);
       format.setMaximumFractionDigits(2);
       String str = "";
       str = name + ", " + format.format(price);
       if (bulkPrice != 0) {
           str += " ( " + bulkQuantity + " for " + format.format(bulkPrice)
                   + " )";
       }
       return str;
   }
}

JAVA Code that needs comments:

public class ItemOrder {
   private final Item item;
   private final int quantity;

   /**
   *
   * @param item
   * @param quantity
   */
   public ItemOrder(Item item, int quantity) {
       this.item = item;
       this.quantity = quantity;
   }

   public double getPrice() {
       return item.priceFor(quantity);
   }

   public Item getItem() {
       return item;
   }

}

Thanks!!

Answer 1

Item.java :

//import java package
import java.text.NumberFormat;
//Java class with name Item
public class Item {
   //fields
   private String name;
   private double price;
   private int bulkQuantity;
   private double bulkPrice;

   /***
   *
   * @param name
   * @param price
   * @param bulkQuantity
   * @param bulkPrice
   */
   //constructor with parameters
   public Item(String name, double price, int bulkQuantity, double bulkPrice) {
       this.name = name;//set name
       this.price = price;//set price
       this.bulkQuantity = bulkQuantity;//set bulk quantity
       this.bulkPrice = bulkPrice;//set bulk price

   }
   //parameterized constructor
   public Item(String name, double price) {
       //checking price
       if (price < 0) {
           //if price is less than 0 then throw exception
           throw new IllegalArgumentException();
       }

       this.name = name;//set name
       this.price = price;//set price

   }

   /***
   *
   * @param quantity
   * @return
   */
   //method priceFor() with one integer parameter named quantity
   public double priceFor(int quantity) {
       double actual = 0;//variable used to store actual price
       //using if else checking quantity
       if (quantity < 0) {
           //if quantity is less than 0 then throw exception
           throw new IllegalArgumentException();
       } else {
           //checking bulk quantity
           if (bulkQuantity != 0) {
               //when bulkQuantity is not 0 then
               //calculate actual price
               actual = (quantity / bulkQuantity) * bulkPrice + (quantity % bulkQuantity) * price;
           } else {
               //when bulkQuantity is zero
               actual = quantity * price;
           }
       }

       return actual;//return variable actual

   }
   //equals() method , this method will compare item name
   public boolean equals(Item ietm) {
       return this.name.equals(ietm.name);
   }
   //method toString()
   @Override
   public String toString() {
       //instance of NumberFormat class
       NumberFormat format = (NumberFormat) NumberFormat.getCurrencyInstance();
       //setting format for fractional digit
       format.setMinimumFractionDigits(2);
       format.setMaximumFractionDigits(2);
       String str = "";//declaring variable for concatenating name and price
       str = name + ", " + format.format(price);
       //checking bulkPrice
       if (bulkPrice != 0) {
           //when bulkPrice is not zero then
           str += " ( " + bulkQuantity + " for " + format.format(bulkPrice) + " )";
       }
       return str;//return variable str
   }
}

**************************************************

ItemOrder.java :

//Java class named ItemOrder
public class ItemOrder {
   //private final fields
private final Item item;
private final int quantity;

/**
*
* @param item
* @param quantity
*/
//constructor with parameters
public ItemOrder(Item item, int quantity) {
this.item = item;//set item
this.quantity = quantity;//set quantity
}
//method to return price
public double getPrice() {
   //calling static method from item class
return item.priceFor(quantity);
}
//This is getter method for the item
public Item getItem() {
return item;
}

}