(PECL ds >= 1.0.0)
Ds\Map::sort — Sorts the map in-place by value
Sorts the map in-place by value, using an optional comparator function.
comparator在第一个参数小于，等于或大于第二个参数时，该比较函数必须相应地返回一个小于，等于或大于 0 的整数。
没有返回值。
Example #1 Ds\Map::sort() example
<?php
$map = new \Ds\Map(["a" => 2, "b" => 3, "c" => 1]);
$map->sort();
print_r($map);
?>
以上例程的输出类似于：
Ds\Map Object
(
[0] => Ds\Pair Object
(
[key] => c
[value] => 1
)
[1] => Ds\Pair Object
(
[key] => a
[value] => 2
)
[2] => Ds\Pair Object
(
[key] => b
[value] => 3
)
)
Example #2 Ds\Map::sort() example using a comparator
<?php
$map = new \Ds\Map(["a" => 2, "b" => 3, "c" => 1]);
$map->sort(function($a, $b) {
return $b <=> $a;
});
print_r($map);
?>
以上例程的输出类似于：
Ds\Map Object
(
[0] => Ds\Pair Object
(
[key] => b
[value] => 3
)
[1] => Ds\Pair Object
(
[key] => a
[value] => 2
)
[2] => Ds\Pair Object
(
[key] => c
[value] => 1
)
)