The Ds\Map::union() function is an inbuilt function in PHP which is used to create a new map which contains the union of two maps.
Syntax:
Ds\Map Ds\Map::union( $map )
Parameters: This function accepts single parameter $map which is used to hold the other map of the instance to combine with the current instance.
Return Value: It returns a map which contains the union of two maps.
Below programs illustrate the Ds\Map::union() function in PHP:
Program 1:
<?php   // Declare a new map $a = new \Ds\Map(["a" => 1, "b" => 3, "c" => 5]);   // Declare another new map $b = new \Ds\Map(["a" => 2, "c" => 3, "d" => 6]);   // Print the Union of two map echo("Union of both map is: \n");   print_r($a->union($b));   ?> |
Output:
Union of both map is:
Ds\Map Object
(
[0] => Ds\Pair Object
(
[key] => a
[value] => 2
)
[1] => Ds\Pair Object
(
[key] => b
[value] => 3
)
[2] => Ds\Pair Object
(
[key] => c
[value] => 3
)
[3] => Ds\Pair Object
(
[key] => d
[value] => 6
)
)
Program 2:
<?php   // Declare a new map $a = new \Ds\Map(["a" => "Geeks", "b" => "for", "c" => "Geeks"]);   // Declare another new map $b = new \Ds\Map(["b" => "Computer", "e" => "Science", "f" => "Portal"]);   // Print the union of two map echo("Union of both map is: \n");   print_r($a->union($b));   ?> |
Output:
Union of both map is:
Ds\Map Object
(
[0] => Ds\Pair Object
(
[key] => a
[value] => Geeks
)
[1] => Ds\Pair Object
(
[key] => b
[value] => Computer
)
[2] => Ds\Pair Object
(
[key] => c
[value] => Geeks
)
[3] => Ds\Pair Object
(
[key] => e
[value] => Science
)
[4] => Ds\Pair Object
(
[key] => f
[value] => Portal
)
)
