我正在尝试制作虚拟商店计划。概要是，如果用户在任何时候输入“q”，程序应该退出。
用户输入“c”后，要求用户输入2个字符的状态，例如CA，NV，WA。如果是其他代码
输入这三个，它属于＆＃34;其他＆＃34;。然后显示购物车中的内容和计算结果 总价格基于折扣并包含税。
问题是程序会询问用户一次物品和数量，然后进入结账模式。每当我放入＆＃39; q＆＃39;时，它就会转到下一行。
以下是代码：
import java.util.Scanner;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.Random;
import java.io.*;
public class virtualStore {
public static void main(String [] args) throws IOException{
/* If the user enters an item number, the program should ask the user to enter how many of that item
they want, and then print the menu again. If at any time the user enters 'q', the program should quit.
Once the user enters 'c', ask the user to enter a 2-character state such as CA, NV, WA. If a code other
than these three is entered, it falls under "other". Then display what is in their cart and the calculated
total price based on discounts and include the tax. You should use the Math.round() and
System.out.printf methods to round numbers and to display to 2 decimal places. */
Scanner keyboard = new Scanner (System.in);
String input;
char c = ' ';
char q = ' ';
//tax rates
double CAtaxRate = .09;
double NVtaxRate = .07;
double WAtaxRate = .065;
double other = .06;
double tax = 0;
//checkout
double checkout = 0;
double total;
double cash = 0;
double change = 0;
//items
double mushrooms = 0.3;
double onions = 0.6;
double watermelon = 2.5;
double cookies = 1;
int item = 0;
//number of items
int numMushrooms = 0;
int numOnions = 0;
int numWatermelon = 0;
int numCookies = 0;
DecimalFormat dollar = new DecimalFormat("#,##0.00");
Scanner scanner = new Scanner(System.in);
System.out.println("Welcome to Alex's Store."
+ " Here is the menu. "
+ "\nEnter the item number to add it to your cart,"
+ " enter \'c\' to checkout or \'q\' to quit. ");
while(true)
//while(c != 'c' && c != 'q')
{
for (item = 1; item < 4; item ++){
System.out.println("Item\t\t\tPrice\t\t\tQuantity");
System.out.println("---------------------------------------------------------");
System.out.println("1. Mushrooms\t\t($0.30/$0.25)\t\t" + numMushrooms);
System.out.println("2. Onions\t\t($0.60/$0.50)\t\t" + numOnions );
System.out.println("3. Watermelon\t\t($2.50/$2.00)\t\t" + numWatermelon);
System.out.println("4. Cookies\t\t($1.00/$0.75)\t\t" + numCookies);
System.out.println("---------------------------------------------------------");
System.out.println("Enter item number between 1 through 4");
System.out.println("or enter 'c' for checkout or 'q' for quit.");
input = keyboard.nextLine();
item = Integer.parseInt(input);
if (input.equals("1"))
{
System.out.println("Enter how many items you want.");
String m = keyboard.nextLine();
numMushrooms = Integer.parseInt(m);
}
else if (input.equals("2"))
{
System.out.println("Enter how many items you want.");
String o = keyboard.nextLine();
numOnions = Integer.parseInt(o);
}
else if (input.equals("3"))
{
System.out.println("Enter how many items you want.");
String w = keyboard.nextLine();
numWatermelon = Integer.parseInt(w);
}
else if(input.equals("4"))
{
System.out.println("Enter how many items you want.");
String co = keyboard.nextLine();
numCookies = Integer.parseInt(co);
}
}
if (numMushrooms > 10)
{
mushrooms = 0.25;
}
else if (numOnions > 10)
{
onions = 0.5;
}
else if (numWatermelon > 10)
{
watermelon = 2;
}
else if (numCookies > 10)
{
cookies = .75;
}
// quit option
String quit = scanner.nextLine();
q = quit.charAt(0);
if (quit.equalsIgnoreCase("q"))
{
System.out.println("Goodbye");
scanner.close();
System.exit(0);
}
// checkout option
String ch = scanner.nextLine();
c = ch.charAt(0);
if (ch.equalsIgnoreCase("c"))
{
//checkout
checkout = numMushrooms * mushrooms + numOnions * onions + numWatermelon * watermelon + numCookies * cookies;
//tax
total = tax * checkout + checkout;
System.out.print("Enter state abbreviations: ");
input = keyboard.nextLine();
PrintWriter outputfile = new PrintWriter("receipt.txt");
outputfile.println("Your cart: ");
outputfile.println("Sub total:$ " + dollar.format(checkout));
if (input.equalsIgnoreCase("CA"))
{
total = CAtaxRate * checkout + checkout;
outputfile.println("Tax Rate: " + CAtaxRate);
outputfile.println("Tax: $" + dollar.format(CAtaxRate * checkout));
outputfile.println("Total is: $" + dollar.format(total));
}
else if (input.equalsIgnoreCase("NV"))
{
total = NVtaxRate * checkout + checkout;
outputfile.println("Tax Rate: " + NVtaxRate);
outputfile.println("Tax: $" + dollar.format(NVtaxRate * checkout));
outputfile.println("Total is: $" + dollar.format(total));
}
else if (input.equalsIgnoreCase("WA"))
{
total = WAtaxRate * checkout + checkout;
outputfile.println("Tax Rate: " + WAtaxRate);
outputfile.println("Tax: $" + dollar.format(WAtaxRate * checkout));
outputfile.println("Total is: $" + dollar.format(total));
}
else if (input.equalsIgnoreCase(input))
{
total = other * checkout + checkout;
outputfile.println("Tax Rate: " + other);
outputfile.println("Tax: $" + dollar.format(other * checkout));
outputfile.println("Total is: $" + dollar.format(total));
}
outputfile.println("-----------------------------------------------------");
input = keyboard.nextLine();
cash = Integer.parseInt(input);
outputfile.println("Enter amount of cash: $" + dollar.format(cash));
change = cash - total;
outputfile.println("Change due: $" + dollar.format(change));
outputfile.println("Thank you for shopping at Alex's store!");
outputfile.close();
FileWriter fw = new FileWriter("receipt.text", true);
PrintWriter pw = new PrintWriter(fw);
pw.println("C:\\Desktop\\Receipt.txt ");
pw.close();
}
}
}
}
答案 0 :(得分：0)
您使用错误的模型来获取用户输入。
尝试做类似的事情：
while(true) {
// Print the menu messages
String input = scanner.readLine();
if(input.equals("c")) {
// Read in and handle state abbreviation
} else if(input.equals("q")) {
System.exit(0);
} else {
int itemNumber = Integer.parseInt(input);
// Parse and handle item number
}
}