我有一个学校的章节作业。我一直在努力让代码工作。除了我的modify（）和remove（）方法之外，代码完美地运行。我一直在尝试我所知道的所有尝试，似乎没有任何工作。如果你能帮助我，我将不胜感激。
这是ItemToPurchase.java的代码
import java.util.Scanner;
public class ItemToPurchase{
private String itemName;
private int itemPrice;
private int itemQuantity;
private int Total;
private String itemDescription;
public ItemToPurchase(){
itemName = "none";
itemPrice = 0;
itemQuantity = 0;
itemDescription = "none";
}
public ItemToPurchase(String itemName, String itemDescription,
int itemPrice, int itemQuantity){
this.itemDescription = itemDescription;
this.itemName = itemName;
this.itemPrice = itemPrice;
this.itemQuantity = itemQuantity;
}
public void setDescription(String itemDescription) {
this.itemDescription = itemDescription;
}
public void setName(String itemName){
this.itemName = itemName;
}
public void setPrice(int itemPrice){
this.itemPrice = itemPrice;
}
public void setQuantity(int itemQuantity){
this.itemQuantity = itemQuantity;
}
public String getDescription() {
return itemDescription;
}
public String getName(){
return itemName;
}
public int getPrice() {
return itemPrice;
}
public int getQuantity(){
return itemQuantity;
}
public int getTotal(){
Total = itemPrice * itemQuantity;
return Total;
}
public void printItemCost(){
System.out.println(itemName + " " + itemQuantity + " @ $" + itemPrice
+ "= $" + itemPrice*itemQuantity);
}
public void printItemDescription() {
System.out.println(itemName + ":" + itemDescription);
}
}
这是我的ShoppingCart.java代码
import java.util.Scanner;
import java.util.ArrayList;
public class ShoppingCart{
private String customerName;
private String currentDate;
private int Total;
private ArrayList <ItemToPurchase> cartItems = new ArrayList<ItemToPurchase>
();
public ShoppingCart(){
customerName = "none";
currentDate = "January 1, 2016";
}
public ShoppingCart(String customerName, String currentDate){
this.customerName = customerName;
this.currentDate = currentDate;
}
public String getCustomerName(){
return customerName;
}
public String getDate() {
return currentDate;
}
public void addItem(ItemToPurchase item){
cartItems.add(item);
//Adds an item to cartItems array. Has parameter ItemToPurchase. Does not
return anything.
}
public void removeItem(String name){ //this does not work.
while (!cartItems.isEmpty()){
for (int i = 0; i < cartItems.size(); ++i){
if (cartItems.get(i).getName().equals(name)){
cartItems.remove(i);
} else {
System.out.println("Item not found in cart. Nothing removed.");
System.out.println("");
break;
}
}
break;
}
//Removes item from cartItems array. Has a string (an item's name)
parameter. Does not return anything.
//If item name cannot be found, output this message: Item not found in cart.
Nothing removed.
}
public void modifyItem(ItemToPurchase item) { //this does not work.
boolean found = false;;
for (ItemToPurchase i: cartItems){
if (i.getName().equals(item.getName())) {
if (i.getQuantity()!=0){
i.setQuantity(item.getQuantity());
}
found = true;
break;
}
}
if (!found){
System.out.println("Item not found in cart. Nothing modified.");
System.out.println("");
}
}
public int getNumItemsInCart(){
int sum = 0;
for (ItemToPurchase i: cartItems){
sum = sum + i.getQuantity();
}
return sum;
//Returns quantity of all items in cart. Has no parameters
}
public int getCostOfCart() {
int sum = 0;
for (ItemToPurchase i: cartItems){
sum = sum + i.getPrice()*i.getQuantity();
}
System.out.println("");
System.out.println("Total: $" + sum);
System.out.println("");
return sum;
//Determines and returns the total cost of items in cart. Has no parameters
}
public void printTotal() {
int Total = 0;
if (cartItems != null && cartItems.size() > 0) {
System.out.println(customerName + "'s Shopping Cart - " + currentDate);
for (ItemToPurchase item: cartItems){
Total = Total + item.getQuantity();
}
System.out.println("Number of Items: " + Total);
System.out.println();
for (ItemToPurchase i: cartItems){
i.printItemCost();
}
getCostOfCart();
} else {
System.out.println(customerName + "'s Shopping Cart - " + currentDate);
System.out.println("Number of Items: 0");
System.out.println();
System.out.println("SHOPPING CART IS EMPTY");
System.out.println("");
System.out.println("Total: $0");
System.out.println("");
}
//Outputs total of objects in cart.
//If cart is empty, output this message: SHOPPING CART IS EMPTY
}
public void printDescriptions() {
System.out.println(customerName + "'s Shopping Cart - " + currentDate);
System.out.println("");
System.out.println("Item Descriptions");
for (ItemToPurchase i: cartItems){
i.printItemDescription();
//Outputs each item's description.
}
System.out.println("");
}
}
这是我的ShoppingCartManager.java代码
import java.util.Scanner;
public class ShoppingCartManager{
public static void printMenu(ShoppingCart shoppingCart, Scanner scnr){
String Input;
int q = 0;
int skipMenu = 0;
do {
if (skipMenu == 0){
System.out.println("MENU");
System.out.println("a - Add item to cart");
System.out.println("d - Remove item from cart");
System.out.println("c - Change item quantity");
System.out.println("i - Output items' descriptions");
System.out.println("o - Output shopping cart");
System.out.println("q - Quit\n");
System.out.println("Choose an option:");
}
Input = scnr.next();
if (Input.equals("a")){
scnr.nextLine();
System.out.println("ADD ITEM TO CART");
System.out.println("Enter the item name:");
String name = scnr.nextLine();
System.out.println("Enter the item description:");
String itemDescription = scnr.nextLine();
System.out.println("Enter the item price:");
int itemPrice = scnr.nextInt();
System.out.println("Enter the item quantity:");
int quantity = scnr.nextInt();
System.out.println("");
scnr.nextLine();
ItemToPurchase item = new ItemToPurchase(name, itemDescription, itemPrice, quantity);
shoppingCart.addItem(item);
skipMenu = 0;
} else if (Input.equals("d")) {
scnr.nextLine();
System.out.println("REMOVE ITEM FROM CART");
System.out.println("Enter name of item to remove:");
String name = scnr.nextLine();
shoppingCart.removeItem(name);
skipMenu = 0;
} else if (Input.equals("c")) {
scnr.nextLine();
System.out.println("CHANGE ITEM QUANTITY");
System.out.println("Enter the item name:");
String name = scnr.nextLine();
System.out.println("Enter the new quantity:");
int quantity = scnr.nextInt();
ItemToPurchase item = new ItemToPurchase();
item.setQuantity(quantity);
shoppingCart.modifyItem(item);
skipMenu = 0;
} else if(Input.equals("i")){
System.out.println("OUTPUT ITEMS' DESCRIPTIONS");
shoppingCart.printDescriptions();
skipMenu = 0;
} else if (Input.equals("o")){
System.out.println("OUTPUT SHOPPING CART");
shoppingCart.printTotal();
skipMenu = 0;
} else if (Input.equals("q")) {
q = 1;
skipMenu = 0;
} else {
System.out.println("Choose an option:");
skipMenu = 1;
}
} while(q != 1);
}
public static void main(String [] args) {
Scanner scnr = new Scanner(System.in);
String userChar;
System.out.println("Enter Customer's Name:");
String customerName = scnr.nextLine();
System.out.println("Enter Today's Date:");
String currentDate = scnr.nextLine();
System.out.println("");
ShoppingCart s = new ShoppingCart();
System.out.println("Customer Name: " + customerName);
System.out.println("Today's Date: " + currentDate);
System.out.println("");
ShoppingCart shoppingCart = new ShoppingCart(customerName, currentDate);
printMenu(shoppingCart, scnr);
}
}