php two dimensional array with sums to table - php

Question

im in serach for a generic piece of code that uses and array
$arr[$key1][$key2] = $value;
output should be like this where "SUM" is not part of the array.
| 1st key2 | 2nd key2 | 3rd key2 | SUM
1st key1 | 10 | 10 | 10 | 30
2nd key1 | 10 | 10 | 10 | 30
3rd key1 | 10 | 10 | 10 | 30
SUM | 30 | 30 | 30 | 90
so i startet an output to see how far i get:
echo '<table width="100%"><thead>';
foreach($arr as $linekey => $line)
{
echo '<tr>';
echo '<th align="center">';
echo '</th>';
foreach($line as $key => $value)
{
echo '<th align="center">';
echo $key;
echo '</th>';
}
echo '<th align="center">';
echo 'SUM'; //adding the SUM column
echo '</th>';
echo '</tr>';
break;
}
echo '</thead><tbody>';
foreach($arr as $key1 => $value1)
{ echo '<tr>';
echo'<td>'.$key1.'</td>';
$sumRow = 0; //reset sumRow
foreach($arr[$key1] as $key2 => $value2)
{
echo'<td>'.round($arr[$key1][$key2],0).'</td>';
$sumRow += $arr[$key1][$key2]; //summing up rows
$sumAll += $arr[$key1][$key2]; //summing up everything
$sumCol += $arr[$key1][$key2]; //where should be this?
}
echo'<td>'.round($sumRow,0).'</td>'; //echo $sumRow
echo '</tr>';
}
echo '</tbody></table>';
this alaredy works but im not sure where to sum the columns

Answer 1

You should use an array $sumCol to gather columns sums:
$sumCol[$key2] += $arr[$key1][$key2];
It size should be as number of columns.
You cannot do it in one loop without an array because you loop over columns index internally, so you could gather only sumRow in one temporary variable (without array).
Then, at the end:
echo '<tr><td>SUM</td>';
foreach($sumCol as $key2 => $value2)
{
echo'<td>'.round($sumCol[$key2],0).'</td>'; //echo $sumCol
}
echo '</tr>';
echo '</tbody></table>';
The other way is to define the second loop where you iterate first over columns and at second, internally, over rows.