java - 如何创建一个数组，提示用户输入 taco 1 的名称，然后输入价格 1？

Question

使用我当前拥有的代码，用户可以一次输入一个炸 Jade 米饼，但是当我运行它时，我将输入第一个炸 Jade 米饼的名称，然后自动列出价格“输入炸 Jade 米饼的价格” 1 到 10。如何解决这个问题。我确信在循环方面我做错了什么。

代码:

import java.util.Scanner;

public class TacoSort {
    //Create a constant amount of temperatures
    public static int NUMBER_OF_TACOS = 10;
    public static int NUMBER_OF_PRICES = 10;
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Scanner keyboard = new Scanner(System.in);
        System.out.println("Welcome to the taco price sorter! Enter 10 taco names and prices and I'll sort it!");

        //Populates array of 10 tacos
        //Prompts user to enter name of each taco
        String[] tacos = new String[NUMBER_OF_TACOS];
        for (int i = 0; i < NUMBER_OF_TACOS+1; i++) 
        {
            System.out.print("Enter the name of taco " + (i+1) + "\n");
            tacos[i] = keyboard.nextLine();

        //Populates array of 10 prices
        //Prompts user to enter price of each taco
        double[] prices = new double[NUMBER_OF_PRICES];
        for (int j = 0; j < NUMBER_OF_PRICES; j++)

            System.out.print("Enter taco's price" + (j+1) + "\n");
            System.out.println("\n");
            prices[i] = keyboard.nextDouble();
        }
    }
}

用户输出应类似于:

Enter the name of taco 1
Crunchy Taco
Enter taco's price
1.19
Enter the name of taco 2
Crunchy Taco Supreme
Enter taco's price
1.59
Enter the name of taco 3
Soft Taco
Enter taco's price
1.19

Answer 1

我对炸 Jade 米饼不太了解(开玩笑，我真的很了解)，但我注意到这里有一些错误的地方。

首先，你的 for 循环应该是:

for (int i = 0; i < NUMBER_OF_TACOS; i++) 

您原本有 i < NUMBER_OF_TACOS + 1 ，这会导致索引越界异常。

其次，您没有正确终止第一个 for 循环的括号；你缺少一个大括号。在第二个 for 循环条件之后，您还缺少一个起始大括号。

第三，您可能应该通过循环检查错误的用户输入，直到用户输入适当的值，并使用类型转换而不是 Scanner#nextDouble() .

最后，您将执行整个第一个循环，然后执行整个第二个循环。如果您希望程序询问 Taco #1 的名称和价格，然后询问 Taco #2 的名称和价格，依此类推，那么您应该在同一循环中询问每个 Taco 的名称和价格。

正确的代码如下所示:

import java.util.Scanner;

public class TacoSort {
    //Create a constant amount of tacos
    public static int NUMBER_OF_TACOS = 10;
    public static void main(String[] args) {

        Scanner keyboard = new Scanner(System.in);
        System.out.println("Welcome to the taco price sorter! Enter 10 taco names and prices and I'll sort it!");

        //Populates array of 10 tacos
        //Prompts user to enter name of each taco
        String[] tacos = new String[NUMBER_OF_TACOS];
        double[] prices = new double[NUMBER_OF_TACOS]; // NOTE Moved this up from below
        for (int i = 0; i < NUMBER_OF_TACOS; i++) // NOTE Fixed off-by-one error
        {
            System.out.print("Enter the name of taco " + (i+1) + "\n");
            tacos[i] = keyboard.nextLine();
            System.out.print("Enter taco's price " + (i+1) + "\n");
            prices[i] = keyboard.nextDouble(); // TODO Fix this so it checks for non-double input?
        } // NOTE Added end-bracket here!

        // Consolidated prices loop into taco names loop

        // Do something with the list of tacos and prices
    }
}