java - 用户定义的方法编译器错误

Question

好吧，如果您不喜欢我的缩进(我是初学者)，现在道歉..

我无法编译此代码。 作业是编写两个用户定义的方法，一个( boolean 值)确定字母是否为元音，另一个将用户输入的 int (例如:12345)更改为相反的(54321) 我对这段代码感到非常困难。 如有建议和提示，我们将不胜感激。

更新:新代码:

import java.util.Scanner;

public class InClassModule8
{
  public static void main(String[] args) {
    Scanner keyboard = new Scanner(System.in);
    System.out.println("Please enter a letter: ");
    String letter = keyboard.nextLine();
    System.out.println("Please enter an integer: ");
    int digit = keyboard.nextInt();
    System.out.println(isVowel(letter));
    System.out.println("The reversed digits are: " + reverseDigit(digit));
    }
}

  private static boolean isVowel(String line) 
  {
    line = (line != null) ? line.trim() : "";
    if (line.length() == 1) {
        switch (Character.toUpperCase(line.charAt(0))) 
        {
        case 'A': case 'E': case 'I': case 'O': case 'U':
            return true;
        }

    return false;
    }

  private static String reverseDigit(int val) 
  {
    StringBuilder sb = new StringBuilder(String.valueOf(val));
    return sb.reverse().toString();
  }

现在的错误:

6 errors found: File: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java [line: 16] Error: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java:16: class, interface, or enum expected File: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java [line: 19] Error: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java:19: class, interface, or enum expected File: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java [line: 24] Error: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java:24: class, interface, or enum expected File: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java [line: 27] Error: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java:27: class, interface, or enum expected File: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java [line: 32] Error: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java:32: class, interface, or enum expected File: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java [line: 33] Error: /Users/gcaruso/Documents/CISS 110/Module 3/Module 4/In_Class_Module_8.java:33: class, interface, or enum expected

Answer 1

您的 main() 有一些额外的调用。我想你只是想要类似的东西

public static void main(String[] args) {
    Scanner keyboard = new Scanner(System.in);
    System.out.println("Please enter a letter: ");
    String letter = keyboard.nextLine();
    System.out.println("Please enter an integer: ");
    int digit = keyboard.nextInt();
    System.out.println(isVowel(letter));
    System.out.println("The reversed digits are: " + reverseDigit(digit));
}

要测试它是否是元音，让我们修剪输出并打开大写字符，例如 -

private static boolean isVowel(String line) {
    line = (line != null) ? line.trim() : "";
    if (line.length() == 1) {
        switch (Character.toUpperCase(line.charAt(0))) {
        case 'A': case 'E': case 'I': case 'O': case 'U':
            return true;
        }
    }
    return false;
}

要反转数字，请将其转换为String，将其添加到StringBuilder，然后reverse()，

private static String reverseDigit(int val) {
    StringBuilder sb = new StringBuilder(String.valueOf(val));
    return sb.reverse().toString();
}