使用Java的回文测试仪，忽略空格和标点符号 [英] Palindrome tester with Java, ignoring spaces and punctuation

问题描述

我已经编写了程序，直到必须忽略它，在线程中使用标点符号和空格为止，我想知道是否有人可以帮助我进行编码?我一直在尝试的东西似乎没有用.这是我到目前为止的内容:

I have the program made up until the point where it has to ignore and punctuations and spaces in the thread and I was wondering if anyone could help me with the coding for that? What I've been trying out doesn't seem to be working. Here is what I have so far:

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();
    }

 }

}

推荐答案

只是为了澄清吉姆·加里森(Jim Garrison)所说的，您需要的正则表达式如下:

Just to clarify what Jim Garrison said, the regex you need is the following

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

这将仅保留字母和数字，并删除空格和标点符号，即m变为"madamimadam"，您可以对该字符串进行常规回文测验.

This will leave only letters and digits and remove whitespace and punctuation, i.e. m will become "madamimadam" and you can run you regular palindrome test on that string.

您可以了解有关正则表达式的更多信息这里

You can learn more about regular expressions here

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