The Ds\Map::first() function of PHP Ds\Map class is used to get the first key-value pair from the Map instance.
Syntax:
Ds\Pair public Ds\Map::first ( )
Parameters: This function does not accepts any parameter.
Return value: It returns a pair of type Ds\Pair which is the first key-value pair from the Map instance. That is the key-value pair present at the front of the Map instance.
Below programs illustrate the Ds\Map::first() function in PHP:
Program 1:
<?php // PHP program to illustrate first() function   $map = new \Ds\Map([1 => "Geeks", 2 => "for",                                 3 => "Geeks"]);   print_r($map->first());   ?> |
Output:
Ds\Pair Object
(
[key] => 1
[value] => Geeks
)
Program 2:
<?php // PHP program to illustrate first() function   $map = new \Ds\Map(["first" => "Geeks", "second" => "for",                                 "third" => "Geeks"]);   print_r($map->first());   ?> |
Output:
Ds\Pair Object
(
[key] => first
[value] => Geeks
)
Reference: http://php.net/manual/en/ds-map.first.php
