c# - Why doesn't my chat filter check words correctly? -

i'm trying make kind of chat filter. wanna check "wo rd" or "w ord" or "w.ord" . if enter "word wo rd" , outputs "**** **** ****" (should "**** ****"). also, if disable dot checking, ignores dots..

here code:

    //rextester.program.main entry point code. don't change it. //compiler version 4.0.30319.17929 microsoft (r) .net framework 4.5  using system; using system.collections.generic; using system.linq; using system.text.regularexpressions;  namespace rextester {     public class program     {         public static void main(string[] args)         {             notallowedwords.add(new worddata("word", true, false));             var input = console.readline();             var splitted = input.split(char.parse(" "));             foreach (string s in splitted) {                 var index = findword(input,s);                 if (index != -1) {                     input = input.replace(s, "****");                 }             }             console.writeline(input);         }          private static int findword (string input, string word) {             var splitted = input.split(char.parse(" "));             bool next = false;             foreach (var w in splitted) {                 foreach (var in notallowedwords) {                     if (a.compareto(word))                          return input.indexof(word);                 }                 if (next) {                     next = false;                     if (w.substring(0, word.length - 1) == word.substring(1))                          return input.indexof(w);                 }                 if (w.last() == word[0])                     next = true;             }             return -1;         }          public static list<worddata> notallowedwords = new list<worddata>();     }      public class worddata {          protected worddata() {             ignorewhitespace = true;         }          public bool compareto(string word) {             var input = word;             if (this.notallowdots) {                 input = input.replace(".","");             }             if (this.ignorewhitespace) {                 input = input.trim();             }             if (input.equals(input, stringcomparison.currentcultureignorecase) && !this.allowedversions.contains(input))                 return true;             return false;         }          public worddata(string word, bool ignorewhitespace = true, bool notallowdots = true, params string[] allowedversions) : base() {             this.allowedversions = allowedversions.tolist();             this.ignorewhitespace = ignorewhitespace;             this.notallowdots = notallowdots;             this.word = word;         }          public string word { get; set;}          private list<string> allowedversions = new list<string>();          public list<string> allowedversions {             {                 return allowedversions;             }         }          public bool ignorewhitespace { get; set;}          public bool notallowdots {get; set;}     } } 

input : word wo.rd wo rd output : **** **** **** **** expected output : **** word ****

here how regex . can use online tool test different patterns http://regexstorm.net/tester

class program {     static void main(string[] args)     {          var notallowedword= new notallowedword("word");          var input = "replace word  wo.rd wor d , wor.d not wordpress .";          var replacedtext = notallowedword.replacenotallowedword(input);          console.writeline(replacedtext);          //output         //replace **** ****also ****and ****but not wordpress .          console.readline();      }      public class notallowedword     {         private readonly string _word;         private readonly regex _wordregex;         private readonly string _replacement;          public notallowedword(string word)         {             _word = word;             _replacement=new string('*',word.length);             _wordregex = buildregexpattern();         }          private regex buildregexpattern()         {             //todo use string builder                             var pattern = "";              //create space , . match pattern               // example given "word" produce "w[ ]*\.*o[ ]*\.*r[ ]*\.*l[ ]*\.*d"             foreach (var c in _word)             {                 pattern = pattern + c + @"[ ]*\.*";             }              var regex = $"({_word}[ ])" + //match word                     $"|({pattern}[ ])" + //match word contains space or .                     $"|({pattern}$)"  //match word @ end of sentence                     ;              //console.writeline(regex);              return new regex(regex);         }          public string replacenotallowedword(string inputtext)         {             return _wordregex.replace(inputtext, _replacement);         }       }   }