Question

使用我目前拥有的代码，用户可以一次输入一个炸玉米饼，但是当我运行它时，我将输入第一个炸玉米饼的名称，然后价格会自动列出＆＃34;输入Taco的价格＆＃34; 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：

输入taco 1的名称   脆脆的炸玉米饼   输入taco的价格
  1.19
  输入taco 2的名称   Crunchy Taco Supreme
  输入taco的价格
  1.59
  输入taco 3的名称   软玉米饼   输入taco的价格
  1.19

Answer 1

我不太了解炸玉米饼（开玩笑，我真的这么做），但是我注意到这里做了一些错误。

首先，你的for循环应该是：

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

您最初拥有i < NUMBER_OF_TACOS + 1，这会导致索引超出范围异常。

其次，您没有正确终止第一个for循环的括号;你错过了一个大括号。在你的第二个for循环条件之后，你也错过了一个起始的大括号。

第三，您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，您要完成整个第一个循环，然后是整个第二个循环。如果您希望您的程序询问Taco＃1的名称和价格，然后是Taco＃2的名称和价格，那么您应该在同一循环中询问每个炸玉米饼的名称和价格，等等。

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
    }
}

Answer 2

您的缩进和大括号不同步。

您可能需要在tacos[i] = keyboard.nextLine();

行之后使用结束括号

你可能想要在for (int j = 0; j < NUMBER_OF_PRICES; j++)行之后的一个开始大括号。

但是仍然没有按照你要求的顺序提出问题。

Answer 3

这是因为你的循环的顺序。此外，您还有许多异常和语法错误。

就目前而言，您需要一个循环，因为数组的长度相同。你们会要求Taco 1，价格1-10，然后是Taco 2，价格1-10等等。

抛弃嵌套循环，你会没事的。

for (int i = 0; i < NUMBER_OF_TACOS; i++) //tacos +1 will go out of bounds! 
{
    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
    System.out.print("Enter taco's price" + (i+1) + "\n");
    System.out.println("\n");
    prices[i] = keyboard.nextDouble();
}

Answer 4

上述代码的逻辑存在一些问题。请仔细研究一下，它运作得很好

import java.util.Scanner;

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) 
    {

        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; i++) 
        {
            System.out.print("Enter the name of taco " + (i+1) + "\n");
            tacos[i] = keyboard.next();

            //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" + (i+1) + "\n");
            System.out.println("\n");
            prices[i] = keyboard.nextDouble();
        }
    }
}

如何创建一个数组，提示用户输入taco 1＆amp;的名称价格1？

4 个答案: