triming.rb

def hoge(a, b, c, e, n)
  [a, b, c, e, n].reject(&:nil?).each(&:strip!)
  p a
  p b
  p c
  p e
  p n
end

hoge("a ", "b ", " c ", "", nil)
# "a"
# "b"
# "c"
# ""
# nil