Ds\Map::intersect
PHP function
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(PECL ds >= 1.0.0)
Creates a new map by intersecting keys with another map
Description
Ds\Map::intersect(Ds\Map $map): Ds\Map
Creates a new map containing the pairs of the current instance whose keys are also present in the given map. In other words, returns a copy of the current instance with all keys removed that are not also in the other map.
A ∩ B = {x : x ∈ A ∧ x ∈ B}
Note
Values from the current instance will be kept.
Parameters
mapThe other map, containing the keys to intersect with.
Return Values
The key intersection of the current instance and another map.
See Also
- Intersection on Wikipedia
Examples
Ds\Map::intersect() example
php
<?php
$a = new \Ds\Map(["a" => 1, "b" => 2, "c" => 3]);
$b = new \Ds\Map(["b" => 4, "c" => 5, "d" => 6]);
var_dump($a->intersect($b));
?>The above example will output something similar to:
output
object(Ds\Map)#3 (2) {
[0]=>
object(Ds\Pair)#4 (2) {
["key"]=>
string(1) "b"
["value"]=>
int(2)
}
[1]=>
object(Ds\Pair)#5 (2) {
["key"]=>
string(1) "c"
["value"]=>
int(3)
}
}