(PECL ds >= 1.0.0)
Ds\Set::intersect — Creates a new set by intersecting values with another set
Creates a new set using values common to both the current instance and another set.
In other words, returns a copy of the current instance with all values removed that
are not in the other set.
A ∩ B = {x : x ∈ A ∧ x ∈ B}
setThe other set.
The intersection of the current instance and another set.
Example #1 Ds\Set::intersect() example
<?php
$a = new \Ds\Set([1, 2, 3]);
$b = new \Ds\Set([3, 4, 5]);
var_dump($a->intersect($b));
?>
以上例程的输出类似于：
object(Ds\Set)#3 (1) {
[0]=>
int(3)
}