Get Length Of Columns in Jagged Array
<p>I have a problem extracting the columns length in jagged array like this:</p>

<p><a href="https://i.stack.imgur.com/FX5m9.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FX5m9.jpg" alt="jagged array"></a></p>

<p>How can I get the length of the 2nd (with index 1 and length 8) or the 5th (index 4 and length 4) column for example? Same with the rows. I need length of a specified row.</p>