php sort by key multidimentional array - php

Question

Supposed I have an array of
array(8) {
[0] =>
array(1) {
'Peter' =>
int(4)
}
[1] =>
array(1) {
'Piper' =>
int(4)
}
[2] =>
array(1) {
'picked' =>
int(4)
}
[3] =>
array(1) {
'peck' =>
int(4)
}
[4] =>
array(1) {
'pickled' =>
int(4)
}
How can I sort this multidimentional array by key example (Peter). I tried using
ksort($arr);
but it just return a boolean
The output that I want
array(8) {
[0] =>
array(1) {
'peck' =>
int(4)
}
[1] =>
array(1) {
'Peter' =>
int(4)
}
[2] =>
array(1) {
'picked' =>
int(4)
}
[3] =>
array(1) {
'pickled' =>
int(4)
}
[4] =>
array(1) {
'piper' =>
int(4)
}
the array should be sorted by key and in ascending order.

Answer 1

Sort with usort like this, check the demo
usort($array,function($a,$b){
return strcmp(strtolower(key($a)),strtolower(key($b)));
});

Answer 2

The ksort() method does an in-place sort. So while it only returns a boolean (as you correctly state), it mutates the values inside $arr to be in the sorted order. Note that based on your expected output, it looks like you want to do a case insensitive search. For that, you need to use the SORT_FLAG_CASE sort flag. So, instead of calling ksort($arr), you instead want to use ksort($arr, SORT_FLAG_CASE). You can see how ksort() uses sort flags, in the sort() method's documentation. Hope that helps!

Answer 3

You can do something like this,
$temp = array_map(function($a){
return key($a); // fetching all the keys
}, $arr);
natcasesort($temp); // sorting values case insensitive
$result = [];
// logic of sorting by other array
foreach($temp as $v){
foreach($arr as $v1){
if($v == key($v1)){
$result[] = $v1;
break;
}
}
}
Demo
Output
Array
(
[0] => Array
(
[peck] => 4
)
[1] => Array
(
[Peter] => 4
)
[2] => Array
(
[picked] => 4
)
[3] => Array
(
[pickled] => 4
)
[4] => Array
(
[Piper] => 4
)
)