PHP | Ds\Map union() Function

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
        )

)

Reference: https://www.php.net/manual/en/ds-map.union.php