Question

我很难弄清楚为什么这段代码在“TOTAL COST”中最终没有加起来。

两个班级：

ShoppingCartPrinter.java和ItemToPurchase.java

我一直得到的结果是“TOTAL COST”全部为0。任何帮助将不胜感激。感谢。

ShoppingCartPrinter.java代码：

import java.util.Scanner;

public class ShoppingCartPrinter {
  public static void main(String[] args) {
  Scanner scnr = new Scanner(System.in);
  int i = 0;
  String productName;
  int productPrice = 0;
  int productQuantity = 0;
  int cartTotal = 0;

  ItemToPurchase item1 = new ItemToPurchase();
  ItemToPurchase item2 = new ItemToPurchase();

  System.out.println("Item 1");
  System.out.println("Enter the item name: ");
  productName = scnr.nextLine();                                         // Sets the variable productName for user input

  System.out.println("Enter the item price: ");
  productPrice = scnr.nextInt();                                         // Set the variable productPrice for user input

  System.out.println("Enter the item quantity: ");
  productQuantity = scnr.nextInt();                                      // Set the variable productQuantity for user user input
  System.out.println("");

  item1.setName(productName);
  item1.setPrice(productPrice);
  item1.setQuantity(productQuantity);

  System.out.println("Item 2");
  System.out.println("Enter the item name: ");
  scnr.nextLine();
  productName = scnr.nextLine();                                         // Set the variable productName for user input

  System.out.println("Enter the item price: ");
  productPrice = scnr.nextInt();                                         // Set the variable productPrice for user input

  System.out.println("Enter the item quantity: ");
  productQuantity = scnr.nextInt();                                      // Set the variable productQuantity for user input
  System.out.println("");

  item2.setName(productName);
  item2.setPrice(productPrice);
  item2.setQuantity(productQuantity);

  cartTotal = (item1.getPrice() * item1.getQuantity()) + (item2.getPrice() * item2.getQuantity());

  System.out.println("TOTAL COST");
  System.out.println(item1.getName() + " " + item1.getQuantity() + " @ $" + item1.getPrice()  + " = $" + (item1.getPrice() * item1.getQuantity()));

  System.out.println(item2.getName() + " " + item2.getQuantity() + " @ $" + item2.getPrice()  + " = $" + (item2.getPrice() * item2.getQuantity()));
  System.out.println("");

  System.out.println("Total: $" + cartTotal);

  return;
   }
}

ItemToPurchase.java

public class ItemToPurchase {
   private String itemName;
   private int itemPrice;
   private int itemQuantity;

public ItemToPurchase() {
  itemName = "none";
  itemPrice = 0;
  itemQuantity = 0;
  return;
}

public void setName(String name) {
  itemName = name;
  return;
}

public void setPrice(int price) {
   itemPrice = 0;
   return;
}

public void setQuantity (int quantity) {
   itemQuantity = 0;
   return;       
}

public String getName() {
  return itemName;
}

public int getPrice() {
  return itemPrice;
}

public int getQuantity() {
   return itemQuantity;
}

public void printItemPurchase() {
  System.out.println(itemQuantity + " " + itemName + " $" + itemPrice +  " = $" + (itemPrice * itemQuantity));
}
}

Answer 1

问题出在setters。您正在为项目分配0（零）。

itemPrice = 0;

和

itemQuantity = 0;

这可以通过以下方式解决：

itemPrice = price;

和

itemQuantity = quantity;

此外，在每个具有return返回类型的方法的末尾，您不需要void语句，尤其是在ItemToPurchase()构造函数中。你可以安全地删除它们。

Answer 2

zybooks 赋值会自动应用 setter，这不是自愿的。只有某些部分的代码可以编辑。我目前正在研究这个项目，并且也遇到了问题。只是想澄清这不是他们设置为 0 的编码器错误

在线购物车java

2 个答案: