You're trying to sort the values of $test as if they are alphanumeric strings (this is what "natural ordering" is) but the aren't strings, they're Arrays. Take another look at it:
PHP Code:
$test = [
0 => ['weight' => '90 kg'],
1 => ['weight' => '92 kg'],
2 => ['weight' => '100 kg'],
3 => ['weight' => '94 kg'],
4 => ['weight' => '98 kg'],
5 => ['weight' => '125 kg']
];
Anything that attempts to sort this by natural order is going to fail because you can't convert an Array to a string. This is why your the last three commands fail.
I also suspect that asort isn't actually working as you intended either.
PHP Code:
php > $test = [
php > 0 => ['weight' => '90 kg'],
php > 1 => ['weight' => '92 kg'],
php > 2 => ['weight' => '100 kg'],
php > 3 => ['weight' => '94 kg'],
php > 4 => ['weight' => '98 kg'],
php > 5 => ['weight' => '125 kg']
php > ];
php > var_dump(asort($test));
php shell code:1:
bool(true)
php > var_dump($test);
php shell code:1:
array(6) {
[2] =>
array(1) {
'weight' =>
string(6) "100 kg"
}
[5] =>
array(1) {
'weight' =>
string(6) "125 kg"
}
[0] =>
array(1) {
'weight' =>
string(5) "90 kg"
}
[1] =>
array(1) {
'weight' =>
string(5) "92 kg"
}
[3] =>
array(1) {
'weight' =>
string(5) "94 kg"
}
[4] =>
array(1) {
'weight' =>
string(5) "98 kg"
}
}
php >
Here's a hint that might get you started in the right direction:
PHP Code:
php > foreach ($test as $k=>&$v){$v = $v['weight'];}
php > unset($v); var_dump($test);
php shell code:1:
array(6) {
[0] =>
string(5) "90 kg"
[1] =>
string(5) "92 kg"
[2] =>
string(6) "100 kg"
[3] =>
string(5) "94 kg"
[4] =>
string(5) "98 kg"
[5] =>
string(6) "125 kg"
}
