ksort
(PHP 4, PHP 5, PHP 7, PHP 8)
ksort — Sort an array by key in ascending order
Description
ksort(array &$array, int $flags = SORT_REGULAR): bool
Sorts array in place by keys in ascending order.
Note:
If two members compare as equal, they retain their original order. Prior to PHP 8.0.0, their relative order in the sorted array was undefined.
Note:
Resets array's internal pointer to the first element.
Parameters
-
array -
The input array.
-
flags -
The optional second parameter
flagsmay be used to modify the sorting behavior using these values:Sorting type flags:
-
SORT_REGULAR- compare items normally; the details are described in the comparison operators section -
SORT_NUMERIC- compare items numerically -
SORT_STRING- compare items as strings -
SORT_LOCALE_STRING- compare items as strings, based on the current locale. It uses the locale, which can be changed using setlocale() -
SORT_NATURAL- compare items as strings using "natural ordering" like natsort() -
SORT_FLAG_CASE- can be combined (bitwise OR) withSORT_STRINGorSORT_NATURALto sort strings case-insensitively
-
Return Values
Always returns true.
Examples
Example #1 ksort() example
<?php
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
ksort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}
?>
The above example will output:
a = orange b = banana c = apple d = lemon
Example #2 ksort() with int keys
<?php $a = [0 => 'First', 2 => 'Last', 1 => 'Middle']; var_dump($a); ksort($a); var_dump($a); ?>
The above example will output:
array(3) {
[0]=>
string(5) "First"
[2]=>
string(4) "Last"
[1]=>
string(6) "Middle"
}
array(3) {
[0]=>
string(5) "First"
[1]=>
string(6) "Middle"
[2]=>
string(4) "Last"
}
See Also
- sort() - Sort an array in ascending order
- krsort() - Sort an array by key in descending order
- The comparison of array sorting functions
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Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.ksort.php
