比较两个字符串的相似性以进行名称验证

Question

I need help with a program that im using to verify a user's names. there has to be a certain level of leniency to accept differences like hyphens, spaces and apostrophes. Currently im removing useless characters to compare the strings but names of completely different characters with the same length are being Ok'd. how do i check to see the names are suing similar characters. after the useless ones have been removed and mushed together.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace name_v
{
    class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine("enter first name");
        string firstname = Console.ReadLine();
        Console.WriteLine("Enter 2nd name");
        string secondname = Console.ReadLine();

        if (firstname == secondname)
        {
            Console.WriteLine("Names are exactly the same");
            Console.ReadLine();
        }


        else
        {

            Console.WriteLine("press enter to Compare");
            Console.ReadLine();
            int numFirstName = firstname.Length;
            int numSecondName = secondname.Length;
            Console.WriteLine("# in 1st = " + numFirstName);
            Console.WriteLine("# in 2nd = " + numSecondName);
            Console.ReadLine();                                                                                                                                                   

            firstname = firstname.Replace(" ", "").Replace("-", "").Replace("'", "").Replace(".", "").ToUpper();
            secondname = secondname.Replace(" ", "").Replace("-", "").Replace("'", "").Replace(".", "").ToUpper();


            Console.WriteLine("Names to be compared as");
            Console.WriteLine(firstname);
            Console.WriteLine(secondname);
            numFirstName = firstname.Length;
            numSecondName = secondname.Length;
            Console.WriteLine("# in 1st = " + numFirstName);
            Console.WriteLine("# in 2nd = " + numSecondName);
            Console.ReadLine();

            int nameLengthDif = numFirstName - numSecondName;     

            if (firstname == secondname)
            {
                Console.WriteLine("Names are the same");
                Console.ReadLine();
            }
            else
            {
                Console.WriteLine("Names are not the same");
                Console.ReadLine();
                        if (nameLengthDif < 3)
                        {
                            Console.WriteLine("But Close enough");
                            Console.ReadLine();
                        }
                        else
                        {
                            Console.WriteLine("And not Close enough");
                            Console.ReadLine();
                        }
            }



        }

    }


}
}

Answer 1

@TestWell gave a great solution for determining character difference, but I just want to show you a much better way to strip characters than stringing .Replace() over and over and over again:

You can just add/remove chars from this array:

private char[] invalid = new char[] {' ','-','_','.'};
private static string cleanString(string input)
{    
   return new string(input.Where(x => !invalid.Contains(x)).ToArray()).ToLower();
}

usage:

 firstname = cleanString(firstname);

or as an extension method:

namespace CustomExtensions
{
 public static class StringExtension
 {
    private static char[] invalid = new char[] {' ','-','_','.'};
    public static string CleanString(this string y)
    {
      return new string(y.Where(x => !invalid.Contains(x)).ToArray()).ToLower();
    }
 }
}

usage:

firstname = firstname.CleanString();

Answer 2

How about

private static int GetDifferenceCount(string firstName, string lastName)
{
    int differences;
    string longestString = firstName;

    if (longestString.Length < lastName.Length)
        longestString = lastName;

    for (int i = 0; i < longestString.Length; i++)
    {
        try
        {
            if (firstName.Substring(i, 1) != lastName.Substring(i, 1))
                differences++;
        }
        catch
            differences++;
    }

    return differences;
}

To return number of different characters. You could then say

if (GetDifferenceCount(firstName, lastName) >= 2)
    // Do something

Completing an action if 2 or more characters are different.

Answer 3

try as following :

char[] firstName = firstName.ToCharArray();
char[] lastName = lastName.ToCharArray();
char[] res = firstName.Except(lastName).ToArray();
if(res.Length < 1)
{
  res = lastName.Except(firstName).ToArray();
}
nameLengthDif = res.Length