From: Josh Cheek <josh.cheek@...>
Date: 2009-11-20T05:56:58+09:00
Subject: Re: Ternary Operator and Arrays

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On Thu, Nov 19, 2009 at 12:29 PM, Marnen Laibow-Koser <marnen@marnen.org>wrote:

>
> It's probably a precedence issue.  Looks like << is binding tighter than
> ?: .
>
> Anyway, you can just do ary = another_array.collect{|x| some_hash[x] ||
> ' '}
>
>
You have to be careful with this, though, because nil and false could be
valid values.

ary = Array.new
some_hash = { 'a' => 1 , 'b' => 2 , 'c' => nil , 'd' => false }
another_array = [ 'a' , 'c' , 'd' , 'e' ]

#if you want nil and false to be valid values, this doesn't do what you
expect
another_array.collect{|x| some_hash[x] || ' ' } # => [1, " ", " ", " "]

#you can set the default to the string, then it will return that if the key
doesn't exist
some_hash.default = ' '
another_array.collect{ |x| some_hash[x] } # => [1, nil, false, " "]

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