This is the input string `23x * y34x2`. I want to insert `&quot; * &quot;` (star surrounded by whitespaces) after every number followed by letter, and after every letter followed by number. So my output string would look like this: `23 * x * y * 34 * x * 2`.

This is the regex that does the job: `@&quot;\d(?=[a-z])|[a-z](?=\d)&quot;`. This is the function that I wrote that inserts the `&quot; * &quot;`.

    Regex reg = new Regex(@&quot;\d(?=[a-z])|[a-z](?=\d)&quot;);   
    MatchCollection matchC;
    matchC = reg.Matches(input);
    int ii = 1;
    foreach (Match element in matchC)//foreach match I will find the index of that match
    {
        input = input.Insert(element.Index + ii, &quot; * &quot;);//since I&#39; am inserting &quot; * &quot; ( 3 characters )
        ii += 3;                                        //I must increment index by 3
    }
    return input; //return modified input

My question how to do same job using .net `MatchEvaluator`? I am new to regex and don&#39;t understand good replacing with `MatchEvaluator`. This is the code that I tried to wrote:

    {
        Regex reg = new Regex(@&quot;\d(?=[a-z])|[a-z](?=\d)&quot;);
        MatchEvaluator matchEval = new MatchEvaluator(ReplaceStar);
        input = reg.Replace(input, matchEval);
        return input;
    }
    public string ReplaceStar( Match match )
    {
        //return What??
    }



All Matchevaluator Solutions on Gang of Coders

Total of 1 Matchevaluator Solutions

How does MatchEvaluator in Regex.Replace work?