C # Regular Expression

IsMaych

Public static void RunIsMatch ()

{

String inputString = "Welcome to the publishers, Wrox Pree Ltd ";

If (Regex. IsMatch (inputString, "wrox pree", RegexOptions. IgnoreCase) // check whether wrox pree exists in inputString. case insensitive.

{

Console. WriteLine ("Match Found ");

}

Else

{

Console. WriteLine ("No Match Found ");

}

}

 

# Region Replce () Usage

Public static void RunReplce ()

{

String input = "Welcome to the publishers, Wrox Pree Ltd ";

Input = Regex. Replace (input, "Wrox Pree", "wrox pree ");

Console. WriteLine (input );
String inputString = "123,456,123,123,789,123,888 ";

Regex regExp = new Regex ("123 ");

InputString = regExp. Replace (inputString, "xxx", 2, 4); // 4 indicates starting from 4th, and 2 indicates replacing up to two times

Console. WriteLine (inputString );

}

# Endregion

 

# Use of Split () in region Regular Expression

Public static void RunSplit ()

{

String inputString = "123, ABC, 456, DEF, 789 ";

String [] splitResults;

SplitResults = Regex. Split (inputString, ", |,"); // Split with commas (,) or commas)

StringBuilder resultBulider = new StringBuilder (32 );

Console. WriteLine (splitResults. Length );

Foreach (string stringElement in splitResults)

{

ResultBulider. AppendFormat ("{0 }:{ 1}", "af", stringElement );

}

Console. WriteLine (resultBulider. ToString ());

}

# Endregion

 

 

/// <Summary>

/// Match all numbers in the string

/// </Summary>

/// <Param name = "regexString"> Format of the string to be matched </param>

/// <Param name = "input"> string to be matched </param>

/// <Param name = "beginning"> enter the character position in the string to start searching. </Param>

/// <Param name = "length"> the substring contains the number of characters in the search. </Param>

Public void RunMatch (string regexString, string input, int beginning, int length)

{

Regex myRegex = new Regex (regexString );

Match matchMade = myRegex. Match (input, beginning, length );

If (matchMade. Length! = Length)

{

Console. Write ("{0}-{1} matching failed", beginning + 1, length );

}

Else

{

Console. WriteLine ("{0}-{1} matched successfully", beginning + 1, length );

}

# Region in the entire string, some of them match successfully. Use matchMade. Success

While (matchMade. Success)

{

Console. Write (matchMade. Value );

MatchMade = matchMade. NextMatch ();

}

# Endregion

}

 

MatchRegular MatchReg = new MatchRegular ();

String inPut = "123,456 ";

String regexString = @ "d +"; // match the number of 0-9 or more

MatchReg. RunMatch (regexString, inPut, 0, 4 );

 

# Region Groups and Capture usage

Public static void RunGroups ()

{

String string1 = "04:03:27 127.0.0.1 LibertyAssociates lily ";

Regex theReg = new Regex (@"(? <Time> (d | :) +) s "+ @"(? <Ip> (d |.) +) s "+ @"(? <Site> (S +) s) "+ @"(? <Site> (S + ))");

// If I use the same site group, a problem occurs. The group that follows will overwrite the previous group.

MatchCollection theMatches = theReg. Matches (string1 );

Foreach (Match theMatch in theMatches)

{

If (theMatch. Length! = 0)

{

Console. WriteLine ("theMatch: {0}", theMatch. ToString ());

Console. WriteLine ("time: {0}", theMatch. Groups ["time"]);

Console. WriteLine ("ip: {0}", theMatch. Groups ["ip"]);

Console. WriteLine ("site: {0}", theMatch. Groups ["site"]); // output lily

Console. WriteLine ("site: {0}", theMatch. Groups ["site"]); // output lily

Foreach (Capture cap in theMatch. Groups [