title: what is the best method to check that multiple values are empty using jq?
body: <p>I'm trying to get a boolean that show me if any value are not empty with jq.</p>
  
  <p>is possible that <code>jq 'if .a and .b =!'</code> return true or false ? any exit code maybe ?</p>
  
  <p>empty:</p>
  
  <pre><code>| jq '.a , .b' 
  []
  []
  </code></pre>