function printUpperTriangular($matrix) {
$rows = count($matrix);
$cols = count($matrix[0]);
for ($i = 0; $i < $rows; $i++) {
for ($j = 0; $j < $cols; $j++) {
if ($i > $j) {
echo "0" . " ";
}
else {
echo $matrix[$i][$j] . " ";
}
}
echo "\n";
}
}
$matrix = array(array(1, 2, 3),
array(4, 5, 6),
array(7, 8, 9));
printUpperTriangular($matrix);
/*
run:
1 2 3
0 5 6
0 0 9
*/