Worst regular expression ever

5/16/2007 8:46:01 AM #

Hey Mads,
I know exactly how you feel. In those time crunch moments I find myself using the mantra "keep your wits about you" as told by <a href="www.cauldwell.net/patrick/blog/">Patrick Caldwell</a>.  Perhaps you can try the following, which you may find cleaner:

\d{4}-\d{2}-\d{2} \d{2}:\d{2}

David Seruyange |

5/16/2007 1:47:44 PM #

Couldn't you just have used DateTime.TryParse? Your regular expression also doesn't check for invalid dates (like 2007-13-45 25:78).

Tommy Carlier |

5/16/2007 7:56:22 PM #

At least change it to:

[0-9][0-9][0-9][0-9]-[0-1][0-9]-[0-3][0-9] [0-2][0-9]:[0-5][0-9]

KG2V |

5/16/2007 8:10:41 PM #

doing some thinking....

For the year part:
[0-9][0-9][0-9][0-9]-  works fine
for the Month
(0?[0-9]|1?[0-2])  should work better - as you wont match stuff like 13
for the Day - now THAT would be fun because of variaing month length, but:
([0-2]?[0-9]|3?[0-1]) should be a bit better (can't enter > 31)

and for 24 hour time

The HOUR part is
([01]?[0-9]|2[0-3])
The Minute would be:
[0-5][0-9]

So - string it together:
[0-9][0-9][0-9][0-9]-(0?[0-9]|1?[0-2])-([0-2]?[0-9]|3?[0-1]) ([01]?[0-9]|2[0-3]):[0-5][0-9]  

KG2V |

5/16/2007 10:06:27 PM #

Did you check out regexlib.com?  It looks like they may have had at least one that would match what you needed.

http://regexlib.com/REDetails.aspx?regexp_id=760

matthew |

5/16/2007 10:30:53 PM #

Yeah - I did say day of month would be "fun" - and I didn't trap for that at all - in fact, besides the Feb problem, you have the April, June, Sept, Nov problem

KG2V |

5/17/2007 12:09:21 AM #

I just noticed that for the MONTH part I had

(0?[0-9]|1?[0-2])

but that can lead to a month 0 - ooops

(0?[1-9]|1?[0-2])

KG2V |

5/18/2007 10:34:08 AM #

And if http://regexlib.com/ didn't have what you needed, don't forget http://regexadvice.com where you can get regex help.

Steve Smith |