each_key

each_key

ri

 ---------------------------------------------------------- Hash#each_key
      hsh.each_key {| key | block } -> hsh
 ------------------------------------------------------------------------
      Calls _block_ once for each key in _hsh_, passing the key as a
      parameter.
 
         h = { "a" => 100, "b" => 200 }
         h.each_key {|key| puts key }
 
      _produces:_
 
         a
         b