Csharp：查找和替换特定字符之间的字符串匹配 || 在使用正则表达式的字符串中

Question

I have a string like:

string originalStringBefore = "http://www.abc.com?a=||ThisIsForRndNumber||&qq=hello&jj=||ThisIsForRndNumberAlso||";

I want every string which comes between ||to be replaced with a random number.

Now, the random number generation is easy, but i can't find the way to write a Regular expression to search the string using a pattern and replace it.

I don't want to do it by string manipulation functions.

Expected Solution/ outcome:

string originalStringAfter = "http://www.abc.com?a=||254877787||&qq=hello&jj=||6594741454||";

Answer 1

It looks like you want this regex:

(?<=\|\|)\w+(?=\|\|)

which finds alphanumeric between ||and leaves strings that contain non-alphanumeric characters (like & ) alone.

Then, in C#:

public String ComputeReplacement(Match m) {
    return RandomNumberString();
}

resultString = Regex.Replace(subjectString, @"(?<=\|\|)\w+(?=\|\|)", new MatchEvaluator(ComputeReplacement));

Answer 2

string originalStringBefore = "http://www.abc.com?a=||ThisIsForRndNumber||&qq=hello&jj=||ThisIsForRndNumberAlso||";

Random r = new Random();
Regex rgx = new Regex(@"\|\|.*?\|\|");
Console.WriteLine(rgx.Replace(originalStringBefore, "||" + r.Next(int.MaxValue) + "||"));

Answer 3

Please find the regular expression replace command pasted below

string result = Regex.Replace(originalStringBefore, @"\|\|.*?\|\|","||ReplaceCharactors||");

how ever to write reguler expression's go through this site hope this wil help you

Thanks.