Question

I am developing a windows application in C#. I have been searching for the solution to my problem in creating a Regex pattern. I want to create a Regex pattern matching the either of the following strings:

XD=(111111) XT=(   588.466)m3 YT=(      .246)m3 G=( 3.6)V N=(X0000000000) M=(Y0000000000) O=(Z0000000000) Date=(06.01.01)Time=(00:54:55) Q=(       .00)m3/hr

XD=(111   ) XT=(   588.466)m3 YT=(      .009)m3 G=( 3.6)V N=(X0000000000) M=(Y0000000000) O=(Z0000000000) Date=(06.01.01)Time=(00:54:55) Q=(       .00)m3/hr

The specific requirement is that I need all the values from the above given string which is a collection of key/value pairs. Also, would like to know the right approach (in terms of efficiency and performance) out of the two…Regex pattern matching or substring, for the above problem.

Thank you all in advance and let me know, if more details are required.

Answer 1

I don’t know C#, so there probably is a better way to build a key/value array. I constructed a regex and handed it to RegexBuddy which generated the following code snippet:

StringCollection keyList = new StringCollection();
StringCollection valueList = new StringCollection();
StringCollection unitList = new StringCollection();
try {
    Regex regexObj = new Regex(
        @"(?<key>\b\w+)      # Match an alphanumeric identifier
        \s*=\s*              # Match a = (optionally surrounded by whitespace)
        \(                   # Match a (
        \s*                  # Match optional whitespace
        (?<value>[^()]+)     # Match the value string (anything except parens)
        \)                   # Match a )
        (?<unit>[^\s=]+      # Match an optional unit (anything except = or space)
        \b                   # which must end at a word boundary
        (?!\s*=)             # and not be an identifier (i. e. followed by =)
        )?                   # and is optional, as mentioned.", 
        RegexOptions.IgnorePatternWhitespace);

    Match matchResult = regexObj.Match(subjectString);
    while (matchResult.Success) {
        keyList.Add(matchResult.Groups["key"].Value);
        valueList.Add(matchResult.Groups["value"].Value);
        unitList.Add(matchResult.Groups["unit"].Value);
        matchResult = matchResult.NextMatch();
    }