How to make regex match space OR end of string?

Question

I need to make a regex to match some liquid volumes like:

water in 17oz container
water in container 17oz

How would you make a regex to match these? I could do just /[0-9]{1,}oz/ but that will also match 90ozonelayers, not that it will happen but I want it to be foolproof.

And /[0-9]{1,}oz / will not do the trick to match it if its in the end of the string.

Possible duplicate of: http://stackoverflow.com/questions/6713310/how-to-specify-space-or-end-of-string-and-space-or-start-of-string — anderas, Mar 12 '14 at 13:49
@KristianRafteseth Consider accepting one of the two Answers or ask for further Detail. This will prevent this Question from getting any more Attention and also show at least some appreciation for the people who took the time to help you. — Andresch Serj, Apr 29 '14 at 08:54

score 1 · Answer 1 · answered Mar 12 '14 at 13:50

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You could use \b to match the word boundary:

/\b[0-9]+oz\b/

answered Mar 12 '14 at 13:50

xdazz

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This is also an incorrect solution, as the word boundary matches any non-word character, ie. `[^a-zA-Z0-9_]`. This means "17oz" from "17ozŵald" would match. – tenub Mar 12 '14 at 13:59
Great fine-grained observation, @tenub. Darn Unicode! :} – J0e3gan Mar 19 '14 at 14:25
@KristianRafteseth: Consider marking this answer accepted so that others know it was exactly what you were looking for...without having to read the comments. – J0e3gan Mar 19 '14 at 14:26

Rhys · Answer 2 · 2014-03-12T14:08:31.260

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[0-9]{1,}oz(\s|\b)

This matches on your two strings, but doesn't match on something like 12ozsdsds.

EDIT:

Noticing that all solutions are slightly flawed, it seems taking a combination of all things, the best might be something like (stolen bits from tenub):

/(?<=\s|^)[0-9]{1,}oz(?=\s|$)/ (use /g to match all occurrences).

17oz - match

abc 17oz def - match

17ozz - no match

abc17oz - no match

edited Mar 12 '14 at 14:08

answered Mar 12 '14 at 13:49

Rhys

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This would match "17oz" in "17ozå". – tenub Mar 12 '14 at 13:52
That's true, although so would xdazz's, and yours matches `asdasd17oz` (As does mine, so correcting to amalgamate the best of all worlds). – Rhys Mar 12 '14 at 13:59
Do note that this would not work for JavaScript due to the lookbehind (although the OP specified PHP so it shouldn't matter). – tenub Mar 12 '14 at 14:15

score 0 · Answer 3 · answered Mar 12 '14 at 13:49

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Simple. Just use:

/[0-9]{1,}oz(?= |$)/

answered Mar 12 '14 at 13:49

tenub

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score 0 · Answer 4 · answered Mar 12 '14 at 13:57

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Matches 34oz, 34 oz and 6oz at the end of the string, but not the 56ozone layer.

([0-9]{0,})(\s{0,})(oz{1})(\s{0,}|$)

answered Mar 12 '14 at 13:57

Andresch Serj

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How to make regex match space OR end of string?

4 Answers4