title: Remove vertical space between sections in a Grouped UITableView
body: <p>I've been searching for this one for quite a while and didn't find a solution that works for me.</p>
  
  <p>I've setup the <code>UITableView</code> as <code>Grouped</code> and each section header will hold a <code>UIView</code> that will be used to represent a <strong>question</strong> on a question-answer application and each section will hold a number of rows that will be used to represent the <strong>answers</strong> to that previous question.</p>
  
  <p>The problem is: there is a vertical spacing between each section group, and I want to remove it.</p>
  
  <p><a href="https://i.stack.imgur.com/KsQCx.png" rel="noreferrer"><img src="https://i.stack.imgur.com/KsQCx.png" alt="Captions on red to explain"></a></p>
  
  <p>I already tried to do like suggested in <a href="https://stackoverflow.com/questions/2817308/reducing-the-space-between-sections-of-the-uitableview">here</a> but looks like it didn't worked.</p>
  
  <p>I also tried using a minimal value for the <code>estimatedHeightForFooterInSection</code> as <code>0.00001</code> as suggested <a href="https://stackoverflow.com/questions/30364067/space-between-sections-in-uitableview">here</a>. But I'm getting the following error:</p>
  
  <p><code>'section footer height must not be negative - provided height for section 1 is -0.000010'</code></p>
  
  <p>Is there a way to make this work without abandoning the strategy (section for question, rows for answers)?</p>