PHP - como puedo identificar el ultimo registro del array

foreach ($total as $key => $value) {

     echo "<td align='right'><strong>".number_format($total[$key],2)."</strong></td>";

};

foreach (array_slice($total, 0, -1) as $key => $value) {

    echo "<td align='right'><strong>".number_format($total[$key],2)."</strong></td>";

};

for ($i = 1; $i <= $array_num; ++$i){

    if($total[$i] != 0){

        echo "<td align='right'><strong>".number_format($total[$i],2)."</strong></td>";

    }else{

        echo "<td></td>";

    }

};

foreach (array_slice($total, 0, -1) as $key => $value) {

    echo "<td align='right'><strong>".number_format($total[$key],2)."</strong></td>";

};