The Ds\Map::ksort() function is an inbuilt function in PHP, which is used to sort the map element in-place by key.
Syntax:
void public Ds\Map::ksort ([ callable $comparator ] )
Parameter: This function accepts single parameter $comparator which contains function according to which the values will be compared while sorting the copy of the Map. The comparator should return the following values based on the comparison of two values passed to it as a parameter:
- 1, if the first element is expected to be less than second element.
- -1, if the first element is expected to be greater than second element.
- 0, if the first element is expected to be equal to the second element.
Return value: This function does not return any value.
Below programs illustrate the Ds\Map::ksort() function in PHP:
Program 1:
<?php // PHP program to illustrate ksort() function   // Declare a Map $map = new \Ds\Map([1 => 20, 3 => 10, 2 => 30]);   // Sort the Map element by key $map->ksort();   // Display the map element print_r($map);   ?> |
Output:
Ds\Map Object
(
[0] => Ds\Pair Object
(
[key] => 1
[value] => 20
)
[1] => Ds\Pair Object
(
[key] => 2
[value] => 30
)
[2] => Ds\Pair Object
(
[key] => 3
[value] => 10
)
)
Program 2:
<?php // PHP program to illustrate ksort() function   // Declare a Map $map = new \Ds\Map(["x" => "Geeks",         "a" => "for", "z" => "Geeks"]);   // Sort the Map element by key $map->ksort();   // Display sorted element print_r($map);   ?> |
Output:
Ds\Map Object
(
[0] => Ds\Pair Object
(
[key] => a
[value] => for
)
[1] => Ds\Pair Object
(
[key] => x
[value] => Geeks
)
[2] => Ds\Pair Object
(
[key] => z
[value] => Geeks
)
)
