PHP マニュアル: Creates a new set by intersecting values with another set

説明

public Ds\Set Ds\Set::intersect(Ds\Set $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}

パラメータ

set: The other set.

戻り値

The intersection of the current instance and another set.

参考

» Intersection on Wikipedia

例

例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));
?>

上の例の出力は、たとえば以下のようになります。

object(Ds\Set)#3 (1) {
  [0]=>
  int(3)
}