title: Explanation of fnFooterCallback for DataTables
body: <p>I am creating a table by using the aaData array that is being loaded by a call to a Neo4j Database. I would like to make a footer row that sums up data in the other rows and I found the fnFooterCallback but I don't understand how they used it. This is the example I found on the DataTables website</p>
  
  <pre><code>$(document).ready( function() { 
      $('#example').dataTable( {
          "fnFooterCallback": function( nFoot, aData, iStart, iEnd, aiDisplay ) {
              nFoot.getElementsByTagName('th')[0].innerHTML = "Starting index is "+iStart;
          }
      } );
  } )
  </code></pre>
  
  <p>I know i put the aaData array where is says aData, but I have no clue where the other four parameters come from. I'm new to datatables and can't find anything in the documentation to explain it other than a stands for array, n for node, and i for integer. </p>
  
  <p>My table is nothing novel. The first column is text explaining what's in the row and the remaining columns contain integers. I simply want a footer that says total in the first column and then displays the sums for all the other columns</p>