Use hash select for an array

Question

I have a hash

h = {a=> 1, b=> 2, c=> 3}

and an array

a = [a, b]

Is it possible to use

h.select {|k,v| k == array_here?}

To select all elements from the array that exists in the hash?

I Found the Solution

h.select {|k,v| a.include?(k) }

Answer 1

You're going about it backwards. Try this:

a.select {|e| h.has_key? e }

Answer 2

You could achieve that with something like:

a.each do |arr_elem| 
  new_hash[arr_elem] = h[arr_elem] unless h[arr_elem].nil?
end