Help with Regex Pattern

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Naveen - 16 Sep 2007 18:08 GMT

Not sure if this is the right forum for this question but couldn'd find
another newsgroup.

I am new to Regular expressions and would like help in deciding which
pattern allows me to split a string into sets of words based on capital
letter.
For e.g. if i have a string "FirstnameLastname" I would like the result to
return me Firstname and Lastname.
The other conditions of the input string are
1) If whitespace exists, do not return a match, instead return the original
string.
2) The first character will always be a capital letter.
3) There may or may not be more than one word in the input string.

Any help will be greatly appreciated.

Thanks.

Reply to this Message

Naveen - 16 Sep 2007 18:32 GMT

By the way, the closest I got was :

string testString = "FirtsnameLastname";
string[] s = Regex.Split(testString, @"[^A-Z]?[a-z]*");

Unfortunately this returns F and L wheras I would like Firstname and
Lastname to be returned.

> Not sure if this is the right forum for this question but couldn'd find
> another newsgroup.
[quoted text clipped - 13 lines]
>
> Thanks.

Reply to this Message

Jesse Houwing - 16 Sep 2007 22:29 GMT

Hello Naveen,

string testString = "FirstnameLastname";
if (teststring.indexOf(" ") == -2)
{
string testString = Regex.Replace(teststring, @"([a-z])([A-Z])", @"$1 $2",
RegexOptions.None);
}

should do the trick. it finds the location of a small character, followed
by a capital character anf inserts a space by splitting them up.

The asiest way to ignore the result if there is a whitespace in teh string
is either checking for a specific space character. A more complicated test
would be:

Regex.Match(testString, "\s", RegexOptions.None).Success

This should test for all possible space characters in the unicode character
set.

If you're using this regex in a time critical way, or use it pretty often
is is better to use an instance of the regex instead of static calls.

private static Regex insertWhitespaceRegex = new Regex(@"([a-z])([A-Z])",
RegexOptions.Compiled);
public static string InsertWhitespace(string testString)
{
if (teststring.indexOf(" ") == -2)
{
string testString = insertWhitespaceRegex.Replace(teststring, @"$1 $2");
}
}

Jesse

> By the way, the closest I got was :
>
[quoted text clipped - 22 lines]
>>
>> Thanks.

--
Jesse Houwing
jesse.houwing at sogeti.n

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Arne Vajhøj - 16 Sep 2007 19:41 GMT

> Not sure if this is the right forum for this question but couldn'd find
> another newsgroup.
[quoted text clipped - 11 lines]
>
> Any help will be greatly appreciated.

For inspiration:

using System;
using System.Text.RegularExpressions;

namespace E
{
public class PascalParse
{
private static Regex pascal = new Regex("[A-Z][a-z]*");
public static void Main(string[] args)
{
string s = "FirtsnameLastname";
foreach(Match m in pascal.Matches(s))
{
Console.WriteLine(m.Value);
}
Console.ReadKey();
}
}
}

Arne

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Help with Regex Pattern

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