<?php
$arr = [
'USA' =>
[
'Alabama' =>
[
'Montgomery',
'Birmingham'
],
'Arizona' =>
[
'Phoenix',
'Mesa',
'Gilbert'
]
],
'Germany' =>
[
'West Germany' =>
[
'Bonn',
'Cologne'
]
]
];
$iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($arr));
$keys = array();
foreach ($iterator as $key => $value) {
// Build long key name based on parent keys
for ($i = $iterator->getDepth() - 1; $i >= 0; $i--) {
$key = $iterator->getSubIterator($i)->key() . '_' . $key;
}
$keys[] = $key;
}
var_export($keys);
- Output for 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.4, 8.3.6
- array (
0 => 'USA_Alabama_0',
1 => 'USA_Alabama_1',
2 => 'USA_Arizona_0',
3 => 'USA_Arizona_1',
4 => 'USA_Arizona_2',
5 => 'Germany_West Germany_0',
6 => 'Germany_West Germany_1',
)
- Output for 8.3.5
- Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
array (
0 => 'USA_Alabama_0',
1 => 'USA_Alabama_1',
2 => 'USA_Arizona_0',
3 => 'USA_Arizona_1',
4 => 'USA_Arizona_2',
5 => 'Germany_West Germany_0',
6 => 'Germany_West Germany_1',
)
- Output for 4.4.2 - 4.4.9, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29
- Parse error: syntax error, unexpected '[' in /in/gtChH on line 2
Process exited with code 255. - Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1, 5.0.0 - 5.0.5
- Parse error: parse error, unexpected '[' in /in/gtChH on line 2
Process exited with code 255. - Output for 4.3.2 - 4.3.4
- Parse error: parse error in /in/gtChH on line 2
Process exited with code 255.
preferences:
203.64 ms | 401 KiB | 313 Q