Ds\Map::keys

(PECL ds >= 1.0.0)

Ds\Map::keys — Returns a set of the map's keys

说明

public Ds\Map::keys ( void ) : Ds\Set

Returns a set containing all the keys of the map, in the same order.

参数

此函数没有参数。

返回值

A Ds\Set containing all the keys of the map.

范例

Example #1 Ds\Map::keys() example

<?php
$map = new \Ds\Map(["a" => 1, "b" => 2, "c" => 3]);
var_dump($map->keys());
?>

以上例程的输出类似于：

object(Ds\Set)#2 (3) {
  [0]=>
  string(1) "a"
  [1]=>
  string(1) "b"
  [2]=>
  string(1) "c"
}
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