PHP Manipulating an Array Sorting an Array
Example
There are several sort functions for arrays in php:
sort()
Sort an array in ascending order by value.
$fruits = ['Zitrone', 'Orange', 'Banane', 'Apfel'];
sort($fruits);
print_r($fruits);
results in
Array
(
[0] => Apfel
[1] => Banane
[2] => Orange
[3] => Zitrone
)
rsort()
Sort an array in descending order by value.
$fruits = ['Zitrone', 'Orange', 'Banane', 'Apfel'];
rsort($fruits);
print_r($fruits);
results in
Array
(
[0] => Zitrone
[1] => Orange
[2] => Banane
[3] => Apfel
)
asort()
Sort an array in ascending order by value and preserve the indecies.
$fruits = [1 => 'lemon', 2 => 'orange', 3 => 'banana', 4 => 'apple'];
asort($fruits);
print_r($fruits);
results in
Array
(
[4] => apple
[3] => banana
[1] => lemon
[2] => orange
)
arsort()
Sort an array in descending order by value and preserve the indecies.
$fruits = [1 => 'lemon', 2 => 'orange', 3 => 'banana', 4 => 'apple'];
arsort($fruits);
print_r($fruits);
results in
Array
(
[2] => orange
[1] => lemon
[3] => banana
[4] => apple
)
ksort()
Sort an array in ascending order by key
$fruits = ['d'=>'lemon', 'a'=>'orange', 'b'=>'banana', 'c'=>'apple'];
ksort($fruits);
print_r($fruits);
results in
Array
(
[a] => orange
[b] => banana
[c] => apple
[d] => lemon
)
krsort()
Sort an array in descending order by key.
$fruits = ['d'=>'lemon', 'a'=>'orange', 'b'=>'banana', 'c'=>'apple'];
krsort($fruits);
print_r($fruits);
results in
Array
(
[d] => lemon
[c] => apple
[b] => banana
[a] => orange
)
natsort()
Sort an array in a way a human being would do (natural order).
$files = ['File8.stack', 'file77.stack', 'file7.stack', 'file13.stack', 'File2.stack'];
natsort($files);
print_r($files);
results in
Array
(
[4] => File2.stack
[0] => File8.stack
[2] => file7.stack
[3] => file13.stack
[1] => file77.stack
)
natcasesort()
Sort an array in a way a human being would do (natural order), but case intensive
$files = ['File8.stack', 'file77.stack', 'file7.stack', 'file13.stack', 'File2.stack'];
natcasesort($files);
print_r($files);
results in
Array
(
[4] => File2.stack
[2] => file7.stack
[0] => File8.stack
[3] => file13.stack
[1] => file77.stack
)
shuffle()
Shuffles an array (sorted randomly).
$array = ['aa', 'bb', 'cc'];
shuffle($array);
print_r($array);
As written in the description it is random so here only one example in what it can result
Array
(
[0] => cc
[1] => bb
[2] => aa
)
usort()
Sort an array with a user defined comparison function.
function compare($a, $b)
{
if ($a == $b) {
return 0;
}
return ($a < $b) ? -1 : 1;
}
$array = [3, 2, 5, 6, 1];
usort($array, 'compare');
print_r($array);
results in
Array
(
[0] => 1
[1] => 2
[2] => 3
[3] => 5
[4] => 6
)
uasort()
Sort an array with a user defined comparison function and preserve the keys.
function compare($a, $b)
{
if ($a == $b) {
return 0;
}
return ($a < $b) ? -1 : 1;
}
$array = ['a' => 1, 'b' => -3, 'c' => 5, 'd' => 3, 'e' => -5];
uasort($array, 'compare');
print_r($array);
results in
Array
(
[e] => -5
[b] => -3
[a] => 1
[d] => 3
[c] => 5
)
uksort()
Sort an array by keys with a user defined comparison function.
function compare($a, $b)
{
if ($a == $b) {
return 0;
}
return ($a < $b) ? -1 : 1;
}
$array = ['ee' => 1, 'g' => -3, '4' => 5, 'k' => 3, 'oo' => -5];
uksort($array, 'compare');
print_r($array);
results in
Array
(
[ee] => 1
[g] => -3
[k] => 3
[oo] => -5
[4] => 5
)
