Online PHP editor | refs for O2O7f

<?php // Everything you enter here will be executed by our servers. Try it! $year = array(2010,2010,2010,2011,2011,2012,2013); $profit = array(100,50,10,80,70,50,40); $sums = array(); for ($i; $i < count($year); $i++) { if (isset($sums[$year[$i]])) { $sums[$year[$i]] += $profit[$i]; } else { $sums[$year[$i]] = $profit[$i]; } } print_r($sums);