I have a multidimensional array like this (please ignore the strlen):
array(2) {
["document"]=>
array(16) {
[0]=>
string(14) "Value1"
[1]=>
string(4) "Value2"
[2]=>
string(30) "Value3"
...
And I want to call "strtoupper" for every element (Value1, Value2, etc.) on each level of the multidimensional array (document, etc.).
I tried array_walk_recursive($array, "strtoupper"); but it doesn't work. But why, what can I do?
As strtoupper does not change the original value, but returns new value instead, you should do this:
array_walk_recursive(
$array,
// pass value by reference.
// Changing it will also reflect changes in original array
function (&$value) { $value = strtoupper($value); }
);
Simple fiddle.
Also this hint is described in manual, see the note on callback parameter description.
array_walk_recursive has not an array as return value, it's designed to change the array directly. But that was wrong apparently.function recurse(array $array): array {
$result = [];
foreach ($array as $key => $value) {
$newKey = is_string($key) ? strtoupper($key) : $key;
if (is_array($value)) {
$result[$newKey] = recurse($value);
} elseif (is_string($value)) {
$result[$newKey] = strtoupper($value);
} else {
$result[$newKey] = $value;
}
}
return $result;
}
$array = [
'document' => [
'Value1',
'Value2',
'Value3'
],
'document2' => [
'Value21',
'Value22',
'document2' => [ 'Value221', 222, 'Value223' ],
23
]
];
$result = recurse($array);
print_r($result);
array_walk_recursive($array, static fn (&$val) => $val = $callback($val));
