Regex Hour:Minute (till 31:59)

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+2 Q:

Regex Hour:Minute (till 31:59)

+4 A:

Try this:

^((?<hours>([012]?\d)|(3[01])):)?(?<minutes>[0-5]?\d)$

You have some problems with your regex. Mostly, you're using * where you shouldn't. This opens the door to many errors. For example, it matches the string "0010203333333".

Kobi 2010-01-18 09:15:39

with just a little fix (3?[01]) it worked!why * opens a way to errors, isn't both equivalent to {0,1}?

serhio 2010-01-18 09:25:13

Not at all. `*` means zero or more times: {0,∞} ! And you don't need `3?[01]` - 0 and 1 are already covered by `[012]?\d`.

Kobi 2010-01-18 09:26:23

ah, yeah... thanks!

serhio 2010-01-18 09:28:02

and `\:` means `[\:]` not just `[:]`?

serhio 2010-01-18 09:34:03

`:` has no special meaning in there, so you don't have to escape that with `\:` (it is mostly ignored by regex engines, because people escape all kind of characters anyway). `[123]` means "one of these characters", but '[3]' just means "one of the character 3" - it is redundant for a single character, it is the same as `3`.

Kobi 2010-01-18 09:37:54

ansaurus

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Regex Hour:Minute (till 31:59)

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