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Sorry for my probably noobish question; I recently started developing with Rails. I checked through the API, documentation, and did a bunch of searches but could not find what I was look for.

Is there a method to check to see if a specific array exists?

For example, 

 array = [] array = [2,3,4] if array.exists? puts "array exists!" else puts "No such thing!" end

Thanks

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  • What do you mean by exists? Has content? Commented Jun 4, 2015 at 14:19
  • No, More like is declared. Commented Jun 4, 2015 at 14:24

4 Answers 4

Reset to default
5

like so:

if defined?(array)

instance variables (eg @array) default to nil, so you can just test them with 

if @array
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1 Comment

Thanks so much for your lightning fast answer!
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Note: By defining your array with array = [], your array will always exist. But if you want to check if array is an Array, you can say array.is_a?(Array)

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0

Try this

a = [1,2,3] a.any? => true a.clear a.any? => false
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Hi fellas i´m newbie at Ruby on Rails but this is the most simple way:

if (defined?(array)) puts "array exists!" else puts "No such thing!" end
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Thanks for the precise example.

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