- var_export: documentation ( source)
<?php
$array = [
[0 => 1, 1 => 5, 3 => null],
[0 => 4, 1 => null, 3 => null],
[0 => null, 1 => 5, 3 => 5]
];
$result = [];
foreach ($array as $row) {
foreach ($row as $k => $v) {
$result[$k] = ($result[$k] ?? 0) + ($v !== null);
}
}
var_export($result);