我一直在使用搜索工具来寻找答案,但在解决了之前的几个问题后,我现在陷入了困境。我能够进行比较并进行调整,但现在我不明白我的程序出了什么问题。
我正处于学习计算机编程的第一年,从 Java 开始。我读过很多人说使用 equalsIgnoreCase
但我们还没有学会它,这就是我现在所接受的教育。我还读过一篇文章说if (discount)
也许比 if (discount == true)
更好但我从未使用过 if 语句而不显示其旁边的变量。
一开始,它给我输入的每个姓名提供折扣,包括不在指定提供折扣的 4 个姓名中的姓名。现在,这 4 个名字(Mike、mike、Diane、diane)中的任何一个都不再提供折扣。
我觉得这是一个非常小的错误,但我似乎无法弄清楚。
import java.util.Scanner;
import java.text.DecimalFormat;
public class PizzaOrder
{
public static void main (String [] args)
{
DecimalFormat formatter = new DecimalFormat("#0.00");
Scanner keyboard = new Scanner (System.in);
String firstName;
boolean discount = false;
int inches;
char crustType;
String crust = "Hand-tossed";
double cost = 12.99;
final double TAX_RATE = .08;
double tax;
char choice;
String input;
String toppings = "Cheese ";
int numberOfToppings = 0;
System.out.println("Welcome to Mike and Diane's Pizza");
System.out.print("Enter your first name: ");
firstName = keyboard.nextLine();
if (firstName == "Mike" || firstName == "mike")
{
discount = true;
}
if (firstName =="Diane" || firstName == "diane")
{
discount = true;
}
System.out.println("Pizza Size (inches) Cost");
System.out.println(" 10 $10.99");
System.out.println(" 12 $12.99");
System.out.println(" 14 $14.99");
System.out.println(" 16 $16.99");
System.out.println("What size pizza would you like?");
System.out.print("10, 12, 14, or 16 (enter the number only): ");
inches = keyboard.nextInt();
if (inches == 10)
{
cost = 10.99;
}
if (inches == 12)
{
cost = 12.99;
}
if (inches == 14)
{
cost = 14.99;
}
if (inches == 16)
{
cost = 16.99;
}
else
System.out.println("You have selected incorrect pizza size.");
System.out.println("You have been assigned 12 inch pizza by default.");
keyboard.nextLine();
System.out.println("What type of crust do you want? ");
System.out.print("(H)Hand-tossed, (T) Thin-crust, or " +
"(D) Deep-dish (enter H, T, or D): ");
input = keyboard.nextLine();
crustType = input.charAt(0);
switch (crustType)
{
case 'H':
case 'h':
System.out.println("You have selected Hand-tossed crust.");
break;
case 'T':
case 't':
System.out.println("You have selected Thin-crust.");
break;
case 'D':
case 'd':
System.out.println("You have selected Deep-dish crust.");
break;
default:
System.out.println("You have selected invalid type of crust.");
System.out.println("You have been assigned Hand-tossed crust by default.");
break;
}
System.out.println("All pizzas come with cheese.");
System.out.println("Additional toppings are $1.25 each,"
+" choose from");
System.out.println("Pepperoni, Sausage, Onion, Mushroom");
System.out.print("Do you want Pepperoni? (Y/N): ");
input = keyboard.nextLine();
choice = input.charAt(0);
if (choice == 'Y' || choice == 'y')
{
numberOfToppings += 1;
toppings = toppings + "Pepperoni ";
}
System.out.print("Do you want Sausage? (Y/N): ");
input = keyboard.nextLine();
choice = input.charAt(0);
if (choice == 'Y' || choice == 'y')
{
numberOfToppings += 1;
toppings = toppings + "Sausage ";
}
System.out.print("Do you want Onion? (Y/N): ");
input = keyboard.nextLine();
choice = input.charAt(0);
if (choice == 'Y' || choice == 'y')
{
numberOfToppings += 1;
toppings = toppings + "Onion ";
}
System.out.print("Do you want Mushroom? (Y/N): ");
input = keyboard.nextLine();
choice = input.charAt(0);
if (choice == 'Y' || choice == 'y')
{
numberOfToppings += 1;
toppings = toppings + "Mushroom ";
}
cost = cost + (1.25*numberOfToppings);
System.out.println();
System.out.println("Your order is as follows: ");
System.out.println(inches + " inch pizza");
System.out.println(crust + " crust");
System.out.println(toppings);
if (discount)
{
System.out.println("You are eligible for $2.00 discount.");
cost -= 2.00;
}
System.out.println("The cost of your order is: $" + formatter.format(cost));
tax = cost * TAX_RATE;
System.out.println("The tax is: $" + formatter.format(tax));
System.out.println("The total due is: $" + formatter.format((tax+cost)));
System.out.println("Your order will be ready for pickup in 30 minutes.");
}
}
最佳答案
要比较字符串,您需要使用.equals()
firstName.equals("Mike") || firstName.equals("mike")
甚至更好
firstName.equalsIgnoreCase("mike")
关于java - 在简单的java程序中使用IF语句来应用折扣,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26349852/