java - 如何修改我的代码以在外部打印在 try-catch 内初始化的变量？

Question

这是我的代码，非常简单。它应该得到 10 个 double ，如果用户输入的不是 double ，则捕获异常，然后从数字中取出平均值:

import java.util.*;

public class QuestionOne {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        double i0, i1, i2, i3, i4, 

i5, i6, i7, i8, i9;

    System.out.println("Please enter a number for each input.");
    try {
        i0 = scan.nextDouble();
        i1 = scan.nextDouble();
        i2 = scan.nextDouble();
        i3 = scan.nextDouble();
        i4 = scan.nextDouble();
        i5 = scan.nextDouble();
        i6 = scan.nextDouble();
        i7 = scan.nextDouble();
        i8 = scan.nextDouble();
        i9 = scan.nextDouble();
        double isum = i0 + i1 + i2 + i3 + i4 + i5 + i6 + i7 + i8 + i9;
        double iresult = isum / 10;
    } catch (InputMismatchException e) {
        System.out.println(e + "\nPlease, enter only numbers.");
    }

    System.out.println("The average of all the 10 numbers is " + isum);
}
}

所以，我正在尝试打印 isum 但显然不能，因为它位于 try-catch 内。经过漫长的一天后，我的大脑陷入困境，当我正要安定下来时，意识到我有这项任务要做。有谁知道我应该如何修改代码才能获取 10 个 double 的平均值并打印它？

Answer 1

不要尝试在 try/catch 之外打印平均值；将其打印在最后的 try block 内。当抛出异常时，您不想打印平均值。用户输入了错误的内容，因此即使您可以打印它，计算也会无效。

try {
    i0 = scan.nextDouble();
    i1 = scan.nextDouble();
    i2 = scan.nextDouble();
    i3 = scan.nextDouble();
    i4 = scan.nextDouble();
    i5 = scan.nextDouble();
    i6 = scan.nextDouble();
    i7 = scan.nextDouble();
    i8 = scan.nextDouble();
    i9 = scan.nextDouble();
    double isum = i0 + i1 + i2 + i3 + i4 + i5 + i6 + i7 + i8 + i9;
    double iresult = isum / 10;

    System.out.println("The average of all the 10 numbers is " + isum);
} catch (InputMismatchException e) {
    System.out.println(e + "\nPlease, enter only numbers.");
}