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标题: JAVA高手帮帮忙 [打印本页]

作者: derrick90 时间: 2009-7-3 10:53 PM
标题: JAVA高手帮帮忙
各位高手帮帮忙，这是小弟的作业题目（英文）请别介意。

Task 1
(a) Define the class Item to store the details of an item sold
in the bookshop. Each object of Item should store the
following information:
· Item number
· Item description
· Selling price
· Quantity on hand
Besides the set and get methods, Item class should
also include:
· A no-argument constructor
· A constructor with parameters
· The method equals that returns true if two objects
contain the same information.
(b) Write a test driver to test the various operations of the
class Item.
Task 2
Create an application program that declares an array of 100
elements of type Item. Your program should provide the
following operations which the user may invoke from a menu:
· Add a new item into the array (duplicate entries are not
allowed).
· Amend the details of an item.
· Search for an item by item number.
· Enter a sales transaction (the quantity on hand has to
be reduced accordingly).
· Input stock received (the quantity on hand has to be
updated accordingly).
· List details of all items – one item’s detail per line, with
line numbering.

红字是我要问的，请帮忙，谢谢。

[ 本帖最后由 derrick90 于 2009-7-4 11:09 AM 编辑 ]

作者: Super-Tomato 时间: 2009-7-3 11:05 PM

原帖由 derrick90 于 2009-7-3 10:53 PM 发表
各位楼主帮帮忙，这是小弟的作业题目（英文）请别介意。

Task 1
(a) Define the class Item to store the details of an item sold
in the bookshop. Each object of Item should store the
following in ...

· A no-argument constructor
· A constructor with parameters

constructor 就是主建構函數

class A {
public function A() {} //這個 A 就是constructor
}

如何初始化 Array 應該去看你的教學課本, 這是基本上所有課本或教學網站都會教的

Search 就使用循環搜索 Array 中每個 Class 中的 item number 屬性值

更改 Class 屬性更加不用說了

作者: derrick90 时间: 2009-7-7 06:37 PM
请帮帮忙，要交了还是有问题，谢谢。
不懂怎样加  Quantity

public class Item {
private int itemNumber;
private String itemDescription;
private double sellingPrice;
private static int quantityOnHand;

      public Item() {
}

public Item(int in,String id,double sp){
         itemNumber=in;
         itemDescription=id;
         sellingPrice=sp;
}

      public int getItemNumber(){
            return itemNumber;
      }
      public void setItemNumber(int sin){
            itemNumber=sin;
      }
      public String getItemDescription(){
            return itemDescription;
      }
      public void setItemDescription(String sid){
            itemDescription=sid;
      }
      public double getSellingprice(){
            return sellingPrice;
      }
      public void setSellingprice(double ssp){
            sellingPrice=ssp;
      }
      public static int getQuantityOnHand(){
            return quantityOnHand;
      }
      public static void setQuantityOnHand(int sqoh){
            quantityOnHand = sqoh;
      }
}

import java.util.Scanner;

public class testItem {

public static void main(String [] args) {
         Scanner input = new Scanner(System.in);
         System.out.print("Enter the number of book:");
         int num = input.nextInt();
         Item[] ItemArray = new Item[num];
         for (int i = 0 ; i < ItemArray.length ; i++){
                  ItemArray = inputItemInfo();
         }

         System.out.println("code description    price    quantity");
      System.out.println("=========================================");
         for (int i = 0; i < ItemArray.length;i++){
                  System.out.printf("%d %s    %.2f    \n", ItemArray.getItemNumber(),ItemArray.getItemDescription(),ItemArray.getSellingprice());
         }
}
public static Item inputItemInfo(){

Scanner input = new Scanner(System.in);
System.out.print("Enter the code :");
int itemNumber = input.nextInt();
System.out.print("Enter the description :");
String itemDescription = input.next();
System.out.print("Enter the selling price :");
float sellingPrice = input.nextFloat();

Item item = new Item(itemNumber,itemDescription,sellingPrice);
return item;
}
}

[ 本帖最后由 derrick90 于 2009-7-7 07:14 PM 编辑 ]

作者: goodday 时间: 2009-7-7 09:10 PM
下在ｐｒｏｐｅｒｔｙ里

private int PQuantity;

public int getSize() { return PQuantity; }
public void setSize(int value) { PQuantity=　PQuantity＋　 value; }

作者: derrick90 时间: 2009-7-7 09:38 PM
解决了，for ..loop 还是不行，谢谢帮忙

作者: Super-Tomato 时间: 2009-7-8 01:58 AM

原帖由 derrick90 于 2009-7-7 09:38 PM 发表
解决了，for ..loop 还是不行，谢谢帮忙

不明白你所說的 for loop 有甚麼不行的

作者: derrick90 时间: 2009-7-15 07:07 PM
帮帮忙，谢谢。。
帮我解决infinite loop的问题

import java.util.*;

public class HandleExceptionDemo {
  public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
boolean continueInput = true;

do {
   try {
      System.out.print("\nEnter an integer: ");
      int number = scanner.nextInt();

      // Display the result
      System.out.println("\nThe number entered is " + number);

      continueInput = false;
   }
   catch (InputMismatchException ex) {
      System.out.println("Try again. (Incorrect input: an integer is required)");

   }
} while (continueInput);
  }
}

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