title: Get all keys from ruby hash
body: <p>In php you can just do <code>$associative_array_keys = array_keys($associative_array)</code></p>
  
  <p>Is there a function to get all hash keys in ruby?</p>
  
  <p>I'm currently mapping my hashes and returning the keys: <code>my_hash_keys = my_hash.map{|k,v| k}</code></p>
  
  <p>Is there a better solution?</p>