jonathans_destructive_my_reverse.rb

def my_reverse( a )
  reversed = []
  length_a = a.length
  for counter in Array.new( length_a )
    last = a.pop
    reversed.push( last )
  end
  
  reversed
end

a = [1,2,3,4]

b = my_reverse a

puts b.inspect
 #==> [4, 3, 2, 1] 

puts a.inspect
 #==> []