I expect this example to match the two characters <and >:
a = "<1acf457f477b41d4a363e89a1d0a6e57@Open-Xchange>"
a.match /[<>]/
# => #<MatchData "<">
It matches only the first character. Why?
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What is your expected result? – Yu Hao Sep 30 '15 at 15:16
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1That's what it does, return only the first matched result. – Sergio Tulentsev Sep 30 '15 at 15:28
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Is this what you want? http://stackoverflow.com/questions/6804557/how-do-i-get-the-match-data-for-all-occurrences-of-a-ruby-regular-expression-in – jrochkind Sep 30 '15 at 16:56
2 Answers
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#match only returns the first match as you have seen as MatchData, #scan will return all matches.
>> a="<1acf457f477b41d4a363e89a1d0a6e57@Open-Xchange>"
=> "<1acf457f477b41d4a363e89a1d0a6e57@Open-Xchange>"
>> a.scan /[<>]/
=> ["<", ">"]
Doon
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@SergioTulentsev Is there a `scan` -like method that returns matchdata? – ciaoben Oct 01 '15 at 07:49
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see @jrochkkind comment, http://stackoverflow.com/questions/6804557/how-do-i-get-the-match-data-for-all-occurrences-of-a-ruby-regular-expression-in shows a way to get them as match data – Doon Oct 01 '15 at 07:58
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Problem
You are misunderstanding your expression. /[<>]/ means:
Match a single character from the character class, which may be either
<or>.
Ruby is correctly giving you exactly what you've asked for in your pattern.
Solution
If you're expecting the entire string between the two characters, you need a different pattern. For example:
"<1acf457f477b41d4a363e89a1d0a6e57@Open-Xchange>".match /<.*?>/
#=> #<MatchData "<1acf457f477b41d4a363e89a1d0a6e57@Open-Xchange>">
Alternatively, if you just want to match all the instances of < or > in your string, then you should use String#scan with a character class or alternation. In this particular case, the results will be identical either way. For example:
"<1acf457f477b41d4a363e89a1d0a6e57@Open-Xchange>".scan /<|>/
#=> ["<", ">"]
"<1acf457f477b41d4a363e89a1d0a6e57@Open-Xchange>".scan /[<>]/
#=> ["<", ">"]
Todd A. Jacobs
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2I think he understands the pattern just fine (meaning, it's not The problem here) – Sergio Tulentsev Sep 30 '15 at 15:34