Obtaining the position (first and last) of a specific value that is not null in a array
<p>I'have the next array:</p>

<pre><code>[null,null,null,null,null,null,2,10,29,43,45,40,54,39,13,1,null,null,null,null,null]
</code></pre>

<p>I need to know what is the first position in that array that is NOT null and the last that is NOT null too.</p>

<p>In this particular example, first will be 6 (counting 0 as position 1) and 15.</p>

<p>Thank you</p>
