I come from the Java world so I was shocked to discover that arrays (http://ruby-doc.org/core/classes/Array.html) does not hava a method contains(object) returning bool.
What is the good way - the Ruby way - of doing that ?
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3You'll find that most methods are named differently. :)Andres Jaan Tack– Andres Jaan Tack2010-11-04 12:30:42 +00:00Commented Nov 4, 2010 at 12:30
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4You might actually want to read documentation before posting questions like this, otherwise you end up looking stupid and/or lazy. Especially if you are going to link to the documentation in the question.Paul Leader– Paul Leader2010-11-04 13:26:16 +00:00Commented Nov 4, 2010 at 13:26
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3I ctrl-fed the page with 'contains', 'bool' (to get methods by return type), 'has' ... no luck. Sorry if I disturbed you in your peace Paul Leader.Frédéric Falliere– Frédéric Falliere2010-11-04 14:25:41 +00:00Commented Nov 4, 2010 at 14:25
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1If that's all you did before posting to SO then it makes you look lazy (hence why your question is rated 0). I'm just suggesting that you might learn rather more if you actually read the docs. In the time it takes to post a question here you could have read most of the Array class documentation, certainly the list of methods right at the top. If I started coding in Java I would not expect every class method to be called the same, and to be able to just ctrl-f for a couple of terms and assume that finding nothing indicates no such thing exists and then be "shocked" at the absence.Paul Leader– Paul Leader2010-11-04 15:59:10 +00:00Commented Nov 4, 2010 at 15:59
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2Paul: Relax. The answers are often obvious; that doesn't mean we're idiots.Andres Jaan Tack– Andres Jaan Tack2010-11-04 20:33:14 +00:00Commented Nov 4, 2010 at 20:33
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4 Answers
array.include?(obj) → true or false
Returns true if the given object is present in self (that is, if any object == anObject), false otherwise.
a = [ "a", "b", "c" ]
a.include?("b") #=> true
a.include?("z") #=> false
This, from the Array class documentation:
Comments
[1,2,3].include? 2
=> true
Comments
ruby-1.9.2-p0 > [1,2,3].include? 3
=> true
ruby-1.9.2-p0 > [1,2,3].include? 33
=> false
3 Comments
nonopolarity
did everybody read the question wrong at first... i thought it was "to check if an object is an array"
Paul Leader
Yep, so did I. Weird, the title is perfectly correct, but my brain skipped the "in".
nonopolarity
could it be while we were typing the answer, the author changed the question.... so question has timestamp which is earlier than our answers, so won't show revision
You can do this:
Array.index("ITEM")
if the result is != de nil the element exists.
Regards.
