title: Testing if a hash has any of a number of keys
body: <p>I was wondering if there was a better way to test if a hash has any keys from an array. I want to use it something like this:</p>
  
  <pre><code>keys = %w[k1 k2 k5 k6]
  none = true if hash.key?(keys)
  </code></pre>
  
  <p>Or am I going to have to loop this?</p>