I have a multidimensional array like this (please ignore the strlen):
JavaScript
x
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?
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Answer
As strtoupper
does not change the original value, but returns new value instead, you should do this:
JavaScript
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.