java - 使用 Java 的回文测试器，忽略空格和标点符号

Question

我已经编写了程序，直到它必须忽略线程中的标点符号和空格，我想知道是否有人可以帮助我编码？我一直在尝试的似乎不起作用。这是我到目前为止所拥有的:

import java.util.Scanner;

public class PalindromeTester
{
public static void main (String[] args)

{

    String str, another = "y";

    int left, right;

    char charLeft, charRight;


    Scanner scan = new Scanner (System.in);


    while (another.equalsIgnoreCase("y")) // allows y or Y

    {

        System.out.println ("Enter a potential palindrome: ");

        str = scan.nextLine();

        left = 0;

        right = str.length() - 1;


        while (left < right)
        {
            charLeft = str.charAt(left);
            charRight = str.charAt(right);


            if (charLeft == charRight)
            {
                left++;
                right--;
            }

            else if (charLeft == ',' || charLeft == '.' ||
 charLeft == '-' || charLeft == ':' ||
 charLeft == ';' || charLeft == ' ')

                left++;

            else if (charRight == ',' || charRight == '.' ||
 charRight == '-' || charRight == ':' ||
 charRight == ';' || charRight == ' ')
                right--;
            else

                break;

        }

    System.out.println();


        if (left < right)
            System.out.println ("That string is NOT a palindrome.");
                        else

            System.out.println ("That string IS a palindrome.");


        System.out.println();

    System.out.print ("Test another palindrome (y/n)? ");

    another = scan.nextLine();
    }

 }

}

Answer 1

只是为了澄清吉姆·加里森所说的内容，您需要的正则表达式如下

String m = "Madam, I'm'',.,.''   Adam";
m = m.toLowerCase().replaceAll("\\W", "");

这将只留下字母和数字，并删除空格和标点符号，即 m 将变成“madamimadam”，您可以对该字符串运行常规回文测试。

您可以了解有关正则表达式的更多信息here