Java-字符串索引超出范围错误

当我试图从用户那里收集字符串输入并将其转换为字符类型时，我不断收到一个超出范围的错误。这是我的密码： 编辑：我的问题还没有回答。我在charAt语句中添加了一个参数，但它仍然不起作用。当我运行它时，它告诉我问题出在第33行。这个问题不是我得到的链接的复制品。我无法理解这个被认为是类似的问题。有人能告诉我33号线出了什么问题吗

//Arthur Fidas
import java.util.Scanner;   //Needed for Scanner class
import java.lang.String;
/**
    This program computes and displays the shipping charges for Fed Ex.
*/

public class FedEx
{
    public static void main (String[] args)
    {
        final double ZONE_A = .6, ZONE_B = 1.0, ZONE_C = 1.25, ZONE_D = 1.4;
        String input;
        char zone;
        String name;
        double weight;
        double total = 0.0;
        int serviceCode;
        int hazardCode;
        double hazardCodeCalculation;

        //Create a Scanner object for keyboard input
        Scanner keyboard = new Scanner (System.in);

        //Prompt user for package weight
        System.out.println("What is the weight of the package?: ");
        weight = keyboard.nextDouble();

        //Prompt user for Zone
        System.out.print("Enter the zone letter: ");
        input = keyboard.nextLine();
        zone = input.charAt(0);

        //Calculate zone price
        switch(zone)
        {
            case 'a':
            case 'A':
                total = weight*ZONE_A;
                break;
            case 'b':
            case 'B':
                total = weight*ZONE_B;
                break;
            case 'c':
            case 'C':
                total = weight*ZONE_C;
                break;
            case 'd':
            case 'D':
                total = weight*ZONE_D;
                break;
            default:
                System.out.println("Please enter A, B, C, or D.");
                break;
        }

        //Prompt user for service charge
        System.out.println("Enter the Special Service number: ");
        serviceCode = keyboard.nextInt();

        //Caculate Service Charge
        if (serviceCode == 1)
        {
            total += 0;
        }
        else if (serviceCode == 2)
        {
            total += 10;
        }
        else if (serviceCode == 3)
        {
            total += 25;
        }
        else
        {
            System.out.println("Please enter 1, 2, or 3.");
        }
        //Prompt user for Hazard Code
        System.out.println("Enter the Hazard Code number :");
        hazardCode = keyboard.nextInt();

        //Calculate Hazard Charge
        switch(hazardCode)
        {
            case 1:
                total += 0;
                break;
            case 2:
                hazardCodeCalculation = total * .1;
                total += hazardCodeCalculation;
                break;
            case 3:
                hazardCodeCalculation = total * .25;
                total += hazardCodeCalculation;
                break;
            default:
                System.out.println("Please enter either 1, 2, or 3.");
                break;
        }
    }
}

---

实际上，我在代码部分发现了一些问题

 //Prompt user for Zone
        System.out.print("Enter the zone letter: ");
        input = keyboard.nextLine();
        zone = input.charAt();

首先，您使用

.nextLine（）

方法进行字符串输入，这可能会产生问题。有关这方面的更多信息，请参阅

另一个问题是，您没有为区域分配任何字符，而是应该在

.charAt（）

方法中传递所需字符的

索引

因此，如果需要输入的
字符串的第一个字符
，您可以通过两种
方法执行此操作。对于另一个字符，请更改
.charAt（）
方法中的索引值

(一)

(二)

如果只想将
一个字符
作为
输入
，则可以采用
字符
输入，而不是
字符串

//Prompt user for Zone
    System.out.print("Enter the zone letter: ");
    zone = keyboard.next().charAt(0);

修正码

此外，如果您能帮助我编写代码，以下面的注释中所示的方式显示最后的计算结果，这将是非常有帮助的：您得到的
超出范围错误的错误堆栈跟踪是什么？
？可能重复的错误来自我要求区域字母并使用用户输入的输入变量。然后尝试使用区域变量将输入变量转换为char，您正在调用的
String#charAt
没有参数，我认为其中一些变量甚至无法编译。同样对于读取输入，最好是
String#equalsIgnoreCase
，或者在使用
switch
的情况下，打开输入的
Character#toLowerCase
之类的内容。@ArttyFidasJr。如果答案对您有帮助，您应该接受。
//Prompt user for Zone
    System.out.print("Enter the zone letter: ");
    input = keyboard.next();  //In case your String input doesn't contain Space in between.
    zone = input.charAt(0);

//Prompt user for Zone
    System.out.print("Enter the zone letter: ");
    zone = keyboard.next().charAt(0);

//Arthur Fidas
import java.util.Scanner;   //Needed for Scanner class
import java.lang.String;
/**
    This program computes and displays the shipping charges for Fed Ex.
*/

public class FedEx
{
    public static void main (String[] args)
    {
        final double ZONE_A = .6, ZONE_B = 1.0, ZONE_C = 1.25, ZONE_D = 1.4;
        String input;
        char zone;
        String name;
        double weight;
        double total = 0.0;
        int serviceCode;
        int hazardCode;
        double hazardCodeCalculation;

        //Create a Scanner object for keyboard input
        Scanner keyboard = new Scanner (System.in);

        //Prompt user for package weight
        System.out.println("What is the weight of the package?: ");
        weight = keyboard.nextDouble();

        /*THIS FOLLOWING PORTION CAN BE CHANGED WITH PROVIDED SOLUTIONS, TRY ANY OF THEM*/

        //Prompt user for Zone                             
        System.out.print("Enter the zone letter: ");
        input = keyboard.next();
        zone = input.charAt(0);

        /*TILL THIS*/

        //Calculate zone price
        switch(zone)
        {
            case 'a':
            case 'A':
                total = weight*ZONE_A;
                break;
            case 'b':
            case 'B':
                total = weight*ZONE_B;
                break;
            case 'c':
            case 'C':
                total = weight*ZONE_C;
                break;
            case 'd':
            case 'D':
                total = weight*ZONE_D;
                break;
            default:
                System.out.println("Please enter A, B, C, or D.");
                break;
        }

        //Prompt user for service charge
        System.out.println("Enter the Special Service number: ");
        serviceCode = keyboard.nextInt();

        //Caculate Service Charge
        if (serviceCode == 1)
        {
            total += 0;
        }
        else if (serviceCode == 2)
        {
            total += 10;
        }
        else if (serviceCode == 3)
        {
            total += 25;
        }
        else
        {
            System.out.println("Please enter 1, 2, or 3.");
        }
        //Prompt user for Hazard Code
        System.out.println("Enter the Hazard Code number :");
        hazardCode = keyboard.nextInt();

        //Calculate Hazard Charge
        switch(hazardCode)
        {
            case 1:
                total += 0;
                break;
            case 2:
                hazardCodeCalculation = total * .1;
                total += hazardCodeCalculation;
                break;
            case 3:
                hazardCodeCalculation = total * .25;
                total += hazardCodeCalculation;
                break;
            default:
                System.out.println("Please enter either 1, 2, or 3.");
                break;
        }
    }
}