如何将字符串转换为char数组，然后将数组返回到另一个类？

Question

我需要程序接受用户字符串，然后在单独的行上输出字符串的每个字符。

这是我的Main类中执行菜单的方法。案例6是我要努力工作的案例。

  private static void executeMenuChoice(int menuChoice, StringManipulator myManipulator)
{
    switch (menuChoice)
    {
        case 1:
            String userUpperCase = myManipulator.listUppercase();
            JOptionPane.showMessageDialog(null, "Your string value converted to uppercase is: " + userUpperCase);
            break;
        case 2:
            String listVowels = myManipulator.listVowels();
            JOptionPane.showMessageDialog(null, "Here are the vowels in your string: " + listVowels);
            break;
        case 3:
            String replaceVowels = myManipulator.replaceVowels();
            JOptionPane.showMessageDialog(null, "Here is your string with values replaced by underscores: " + replaceVowels);
            break;
        case 4:
            int countVowels = myManipulator.countVowels();
            JOptionPane.showMessageDialog(null, "Here is the number of vowels in your string: " + countVowels);
            break;
        case 5:
            String reverseString = myManipulator.reverseString();
            JOptionPane.showMessageDialog(null, "Here is your string in reverse: " + reverseString);
            break;
        case 6:
            char[] character = myManipulator.newlineString();
            JOptionPane.showMessageDialog(null, "Here is your string with each character on a separate line: " + character);
            break;
        case 7:
            JOptionPane.showMessageDialog(null, "You are now exiting the program.");
            break;
    }

这是第二个类中的方法，用于将用户字符串转换为char数组，以在不同的行上输出字符串的每个字符。

        public char[] newlineString() {

    String newLine = getUserString();

    char[] chars = newLine.toCharArray();

    return chars;
}

Answer 1

我认为问题在于您正在尝试将数组连接到文本字符串。

尝试这样：

case 6:
        char[] character = myManipulator.newlineString();
        JOptionPane.showMessageDialog(null, 
               "Here is your string with each character on a separate line: " +
                String.join("\n", character));
        break;