(PECL ds >= 1.0.0)
Ds\Map::first — Returns the first pair in the map.
Returns the first pair in the map.
此函数没有参数。
The first pair in the map.
UnderflowException if empty.
Example #1 Ds\Map::first() example
<?php
$map = new \Ds\Map(["a" => 1, "b" => 2, "c" => 3]);
var_dump($map->first());
?>
以上例程的输出类似于:
object(Ds\Pair)#2 (2) { ["key"]=> string(1) "a" ["value"]=> int(1) }