How to split string exactly with pattern matching case

Question

Hi All, 

I am facing bit problem to split string with pattern matching case here. I want to split string with pattern matching case only here. please help me here. 

List<string> pattern = new List<string>();
            pattern.Add("[__]");

            string studentInfo = "[__] Student Attendance \n[__] Student Lunch Time\n(**) Parents Meeting Date \n[__] Student Play time\n[__] Student Library time, \n(**) Parents Observation \n";

            var finalStudentList = Regex.Split(studentInfo, string.Join("|", pattern.Select(c => Regex.Escape(@"" + c + "")).ToArray())).Where(s => s != string.Empty).ToArray<string>();
            string report = Environment.NewLine + string.Join(Environment.NewLine, finalStudentList);

Here it's returning below string

string report = "\r\n Student Attendance \n\r\n Student Lunch Time\n(**) Parents Meeting Date \n\r\n Student Play time\n\r\n Student Library time, \n(**) Parents Observation \n";

but i don't want "(**) Parents Meeting Date \n" and "(**) Parents Observation \n"

my output should be like below

string report = "\r\n Student Attendance \n\r\n Student Lunch Time\n\r\n Student Play time\n\r\n Student Library time, \n"

what should i need to do here. Please help me

Thanks,
Chandu

Answer 1

Your pattern in serving two purposes. It is determining the split and it is removing the funky characters ("[__]"). You also want to exclude some of the items. That needs to be done in another way. I suggest you approach it a bit differently and deal with the split in one way and removal of funky characters another way, 

            List<string> removalPattern = new List<string>();
            removalPattern.Add(@"[__]");
            removalPattern.Add(@"(**)");
            string exclusionPattern = "(**)";
            string studentInfo = "[__] Student Attendance \n[__] Student Lunch Time\n(**) Parents Meeting Date \n[__] Student Play time\n[__] Student Library time, \n(**) Parents Observation \n";
            var StudentList = Regex.Split(studentInfo, "\n").Where(s => !s.Contains(exclusionPattern) && s != string.Empty);
            var finalStudentList = StudentList.Select(s => s.Replace(removalPattern[0], "")).Select(s => s.Replace(removalPattern[1], ""));
            string report = Environment.NewLine + string.Join(Environment.NewLine, finalStudentList);

This is clunky, but seems to work.

Ethan

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Ethan Strauss

Answer 2

Try this too:

string report = string.Join( Environment.NewLine, Regex.Matches( studentInfo, @"(?<=\[__\]).+?(\n|$)" ).Cast<Match>().Select( m => m.Value ).Where( s => !string.IsNullOrWhiteSpace( s ) ) );

Answer 3

Hi Ethan, 

Thanks for u'r reply. But here "exclusionPattern" is not fixed. I will be getting multiple kind of patterns in string like it could be (...), [__], (/), etc. But here one pattern should be fixed, according to that i need to split the string. Remaining pattern matching string text i have to remove.  

Answer 4

That makes sense, but how will you know what to exclude and what to include? Is it only things with "[__]"? If so,

    var StudentList = Regex.Split(studentInfo, "\n").Where(s => !s.Contains(exclusionPattern) && s != string.Empty);

to

    var StudentList = Regex.Split(studentInfo, "\n").Where(s => s.Contains(inclusionPattern) && s != string.Empty);

If there is some other way to tell what to include or exclude you need to add appropriate logic in somewhere.

Ethan

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Ethan Strauss