c# - Compare and validate two strings -

// = alphabetic, x = alphanumeric, n = numeric character  string strformatching = "aaaaxxxx-nnnn-aa";  string[] strtobevalidated = new string[] {     "333test",     "test4444-1234-ab",     "abcd12ab-1234-99",     "abcd2345-1234-ab",     "ppp12aa-9876" }; 

with for loop passing each string string array method

public bool validatestring(string strformatching, string strtobevalidated) {     bool isvalid = false;      // put here?      return isvalid; } 

i want validate strtobevalidated strformatching.

that means:

• 333test not valid
• abcd2345-1234-ab valid
• ppp12aa-9876 valid
• ppppp12ax-1234-ab not valid.

what ever value there should match strformatching. need validate separator.

i can not use regular expression because have aaaaxxx-nnnn-aa, in case 1 4 alphabet okay valid more 4 alphabet not valid same x , n , separate can change / or # or @ anything. if i'll use regular expression check till fix length

this regular expression seems work expected

string[] strtobevalidate = new string[] {"333test", "test4444-1234-ab", "abcd12ab-1234-99", "abcd2345-1234-ab", "ppp12aa-9876" }; regex r = new regex(@"[a-za-z]{4}[a-za-z0-9]{4}-[0-9]{4}-[a-za-z]{2}"); foreach(string s in strtobevalidate) {     match m = r.match(s);     if(m.success == false)         console.writeline("no match for: " + s);     else         console.writeline(m.tostring());  } 

meaning:

• first set of 4 characters {4} should in range a-z (upper case) or a-z (lower case)
• the second set of 4 character should before contains numbers 0-9
• a minus symbol follow
• the third set of 4 characters numbers
• a minus symbol follow
• the fourth set of 2 characters alphabetich characters

now applying regex pattern input strings find match second , fourth string.

looking @ comment have tried build simple pattern builder.

string buildpattern(string h) {     stringbuilder sb = new stringbuilder();     string curpattern = "";     char curchar = ' ';     int cnt = 0;     foreach(char c in h)     {         if(c != curchar && cnt != 0)         {             sb.append(curpattern);             sb.append("{" + cnt.tostring() + "}");             cnt = 0;             curpattern = "";         }         curchar = c;         switch(c)         {             case 'a':                 curpattern = "[a-za-z]";                 cnt++;                 break;             case 'x':                 curpattern = "[a-za-z0-9]";                 cnt++;                 break;             case 'n':                 curpattern = "[0-9]";                 cnt++;                 break;             default:                 sb.append(c);                 break;         }     }     sb.append(curpattern);     sb.append("{" + cnt.tostring() + "}");     return sb.tostring(); } 

and change code prepare regex pattern one:

string strformatching = "aaaannaa-nnnn-nn"; string pattern = buildpattern(strformatching); // fixed -> regex r = new regex(@"[a-za-z]{4}[a-za-z0-9]{4}-[0-9]{4}-[a-za-z]{2}"); // dynamic pattern  regex r = new regex(pattern); 

however need tested more extensively......