title: how to push a variable into array - Insert blank row in a spreadsheet
body: <p>According to this post <a href="https://stackoverflow.com/questions/38531722/insert-row-between-different-data">Insert row between different data</a> I'm able to insert an empty data row between some rows in a spreadsheet (based on a condition).</p>
  
  <p>I'm trying to make this script adaptable based on the number of columns.</p>
  
  <p>I mean, if I have 3 columns I have to write</p>
  
  <pre><code>newValues.push(['','','']);
  </code></pre>
  
  <p>If I have 5 columns (i.e.) I have to change in </p>
  
  <pre><code>newValues.push(['','','','','']);
  </code></pre>
  
  <p>I want to make this change automatic.
  I've tried with something like</p>
  
  <pre><code>var blankRow = ' " " ';
  
  for (var x = 0; x&lt;lastCol; x++){
  blankRow = blankRow + ',""';
  }
  
  .....
  
  newValues.push([blankRow]);
  </code></pre>
  
  <p>when I run the script gives me an error.</p>
  
  <p>Any idea how can I do?
  Thanks!</p>