How do you match one of two words in a regular expression?

Question

I want to match either @ or 'at' in a regex. Can someone help? I tried using the ? operator, giving me /@?(at)?/ but that didn't work

[Regular expression containing one word or another](http://stackoverflow.com/q/17166618/995714) — phuclv, Mar 11 '16 at 09:29

score 80 · Accepted Answer · answered Jul 27 '09 at 14:34

80

Try:

/(@|at)/

This means either @ or at but not both. It's also captured in a group, so you can later access the exact match through a backreference if you want to.

answered Jul 27 '09 at 14:34

Michael Myers

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would this handle cases where the email address is something like [email protected], or latitudeataddress.com? – Josh E Jul 27 '09 at 14:50
Why wouldn't it? What do you mean by "handle"? – Michael Myers Jul 27 '09 at 14:56
would it produce false positive matches is what I'm asking I guess. – Josh E Jul 27 '09 at 15:17
1

Of course it would produce false positives! Regular expressions can't read your mind. – innaM Jul 27 '09 at 15:18
right... so then would the OP be better served with a regex that attempts to reduce that possiblity in your opinion? I think that you could improve upon it, but at the cost of increased complexity. Would that be worth it though? – Josh E Jul 27 '09 at 15:21

score 43 · Answer 2 · answered Jul 27 '09 at 14:35

43

/(?:@|at)/

mmyers' answer will perform a paren capture; mine won't. Which you should use depends on whether you want the paren capture.

answered Jul 27 '09 at 14:35

chaos

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Is it some kind of lookaround? I haven't found "?:". Damn google. – Qwerty Mar 12 '13 at 11:57
5

@Qwerty: `(?:)` is grouping without capture, as opposed to `()` that captures. – chaos Mar 12 '13 at 16:33

score 4 · Answer 3 · answered Jul 27 '09 at 14:46

4

if that's only 2 things you want to capture, no need regex

if ( strpos($string,"@")!==FALSE || strpos($string,"at") !==FALSE ) {
  # do your thing
}

answered Jul 27 '09 at 14:46

ghostdog74

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True. I was assuming this was part of something bigger, but if not, this is probably better. – Michael Myers Jul 27 '09 at 14:50

score 3 · Answer 4 · answered Jul 27 '09 at 14:35

3

have you tried

@|at

that works for (in the .NET regex flavor) the following text

[email protected] johnsmithatgmail.com

answered Jul 27 '09 at 14:35

Josh E

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This will also match `[email protected]` Is there a way to match either one but not both in a row? My use case is routing for someone with a nickname. I need to match `www.domain.com/name` and `www.domain.com/nickname` but not `www.domain.com/namenickname`. – Costa Michailidis May 14 '15 at 23:30

score 1 · Answer 5 · answered Oct 02 '18 at 22:47

1

What about:

^(\w*(@|at))

For:

johnsmith@ gmail.com
johnsmithatgmail.com
jonsmith@ atgmail.com

answered Oct 02 '18 at 22:47

Erick Asto Oblitas

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How do you match one of two words in a regular expression?

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