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我試圖通過printMenu(cart, scnr).的Java ArrayList和類
但是，例如「A」>代碼打印
輸入項目名稱： 輸入項目描述：
採取項目名稱之前!!!!
預先感謝您。
這是主類：
import java.util.Scanner;
public class ShoppingCartManager {
public static void main(String[] args) {
Scanner scnr = new Scanner(System.in);
String customerName = "none";
String currentDate = "January 1, 2016";
System.out.println("Enter Customer's Name: ");
customerName = scnr.nextLine();
System.out.println("Enter Today's Date: ");
currentDate = scnr.nextLine();
ShoppingCart cart = new ShoppingCart(customerName, currentDate);
System.out.println("Customer Name: " + cart.getCustomerName());
System.out.println("Today's Date: " + cart.getDate());
printMenu(cart, scnr);
}
public static void printMenu(ShoppingCart cart, Scanner scnr) {
ItemToPurchase cartItems = new ItemToPurchase();
char userChoice = '?';
System.out.println("");
System.out.print("MENU" + "\na - Add item to cart" + "\nd - Remove item from cart"
+ "\nc - Change item quantity" + "\ni - Output items' descriptions"
+ "\no - Output shopping cart" + "\nq - Quit");
System.out.println("");
System.out.println("");
System.out.println("");
System.out.println("Choose an option: ");
userChoice = scnr.next().charAt(0);
boolean rePrintMenu = true;
do {
switch (userChoice) {
// Add item to cart.
case 'a':
System.out.println("ADD ITEM TO CART");
System.out.println("Enter the item name: ");
cartItems.setName(scnr.nextLine());
System.out.println("\n\nEnter the item description: ");
cartItems.setDescription(scnr.nextLine());
System.out.println("\n\nEnter the item price: ");
cartItems.setPrice(scnr.nextInt());
System.out.println("Enter the item quantity: ");
cartItems.setQuantity(scnr.nextInt());
break;
// Remove item from cart
case 'd':
System.out.println("REMOVE ITEM FROM CART");
System.out.println("Enter name of item to remove: ");
cart.removeItem(scnr.nextLine());
break;
// Change item quantity
case 'c':
//ItemToPurchase newQuantity = new ItemToPurchase();
System.out.println("CHANGE ITEM QUANTITY");
System.out.println("Enter the item name: ");
// cart.modifyItem(scnr.nextLine());
break;
// Output items' descriptions
case 'i':
System.out.println("OUTPUT ITEMS' DESCRIPTIONS");
System.out.println(cart.getCustomerName() + "'s Shopping Cart - " + cart.getDate());
System.out.println("");
System.out.println("");
System.out.println("Item Descriptions");
System.out.println(cart.printDescriptions());
System.out.println();
break;
case 'o':
System.out.println("OUTPUT SHOPPING CART");
System.out.println(cart.getCustomerName() + "'s Shopping Cart - " + cart.getDate());
System.out.println(cart.getNumItemsInCart());
System.out.println("");
System.out.println("");
System.out.println(cart.printTotal());
break;
case 'q':
rePrintMenu = false;
System.exit(0);
break;
}
} while (rePrintMenu);
return;
}
}
enter code here
這是我的購物車！
但我不知道爲什麼它不適用於main。另外，如何通過名稱刪除項目？
我想這個邏輯，但沒有奏效：
對於（）{ 如果（）
其他{}
我應該有布爾標誌？或計數？我迷路了。
import java.util.ArrayList;
public class ShoppingCart {
private String customerName = "none";
private String currentDate = "January 1, 2016";
private ArrayList<ItemToPurchase> cartItems = new ArrayList<ItemToPurchase>();
public ShoppingCart() {
}
public ShoppingCart(String userName, String userDate) {
customerName = userName;
currentDate = userDate;
return;
}
public String getCustomerName() {
return customerName;
}
public String getDate() {
return currentDate;
}
public void addItem(ItemToPurchase item) {
cartItems.add(item);
return;
}
//fixMe
public void removeItem(String itemName) {
return;
}
// fixMe
public void modifyItem(ItemToPurchase item) {
return;
}
public int getNumItemsInCart() {
int totalNumOfItem = 0;
for (int i = 0; i < cartItems.size(); ++i) {
totalNumOfItem += cartItems.get(i).getQuantity();
}
return totalNumOfItem;
}
public int getCostOfCart() {
int cartCost = 0;
for (int i = 0; i < cartItems.size(); ++i) {
cartCost += cartItems.get(i).getQuantity();
cartCost *= cartItems.get(i).getPrice();
}
return cartCost;
}
public int printTotal() {
int total= 0;
for (int i = 0; i < cartItems.size(); ++i) {
if (cartItems.size()> 0) {
cartItems.get(i).printItemCost();
total = (cartItems.get(i).getQuantity()) * (cartItems.get(i).getPrice());
System.out.println("Total: $" + total);
}
else {
System.out.println("SHOPPING CART IS EMPTY");
}}
return total;
}
public String printDescriptions() {
String descriptions = "";
for (int i = 0; i < cartItems.size(); ++i) {
descriptions = cartItems.get(i).printItemDescription();
}
return descriptions;
}
}
這是ItemToPurchase類。
public class ItemToPurchase {
private String itemName = "none";
private String itemDescription = "none";
private int itemPrice=0;
private int itemQuantity=0;
public ItemToPurchase() {
}
public void setName(String userItemName) {
itemName = userItemName;
return;
}
public void setDescription(String userItemDescription) {
itemDescription = userItemDescription;
return;
}
public void setPrice(int userItemPrice) {
itemPrice = userItemPrice;
return;
}
public void setQuantity(int userItemQuantity) {
itemQuantity = userItemQuantity;
return;
}
public String getName() {
return itemName;
}
public String getDescription() {
return itemDescription;
}
public int getPrice() {
return itemPrice;
}
public int getQuantity() {
return itemQuantity;
}
public void printItemCost() {
System.out.print(itemName);
System.out.print(" " + itemQuantity + " @ $" + itemPrice);
System.out.println(" = $" + (itemQuantity * itemPrice));
return ;
}
public String printItemDescription() {
String descriptionForItem = itemName + ": " + itemDescription;
System.out.println(descriptionForItem);
return descriptionForItem;
}
}
嘗試給第一個輸入後的scanner.nextLine（）... –
同樣的問題。然後nextLine。然而，我試過使用兩臺掃描儀，它的工作原理，但兩臺掃描儀的行爲如何？ – 12uedhdksh24
檢查此鏈接..你會明白：http://stackoverflow.com/questions/23450524/java-scanner-doesnt-wait-for-user-input –