title: How to remove null value in array for BigQuery?
body: <p>I have a query about BigQuery,
  Please see the example below:</p>
  <pre><code>SELECT SPLIT(path, '/')[OFFSET(0)] part1,
     SPLIT(path, '/')[OFFSET(1)] part2,
     SPLIT(path, '/')[OFFSET(2)] part3,
     SPLIT(path, '/')[OFFSET(3)] part4,
     ARRAY_LENGTH(SPLIT(path, '/')),
     SPLIT(path, '/') 
  FROM (SELECT &quot;/a/b/&quot; path)
  </code></pre>
  <p>As seen below, the result is like this.
  The question is, how can I remove the part1 and part 4 data,
  and make the f0_ a 2 but not 4?</p>
  <p><a href="https://i.stack.imgur.com/DIUdg.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DIUdg.png" alt="" /></a></p>