Question

I’m trying to create a Hash from local variables (tossing out vars that don’t exist). Something like this:

foo = "bar"
baz = "qiz"

["foo", "baz", "nothing"].something_awesome

#=>
{"foo" => "bar", "baz" => "qiz"}

I’ve tried a bunch of different combinations from Array and Enumerable, but can’t find the right combo. Any ideas?

Thanks for your help!

Answer 1

Building on top of Jin’s answer is a slightly more idiomatic version that swallows exceptions:

ree-1.8.7-2011.03 :042 > foo, bar = 'bar', 'quz'
=> ["bar", "quz"] 
ree-1.8.7-2011.03 :043 > %w(foo bar nothing).reduce({}) { |acc, item| acc[item] = eval(item) rescue nil; acc }.reject { |k, v| v.nil? }
=> {"foo"=>"bar", "bar"=>"quz"} 

IMHO though eval should feel dirty/risky and you might want to reconsider your approach in general.