php get intersection of arrays

$array1 = [1, 2];
$array2 = [2, 3, 4];
$commonValue = array_intersect($array1, $array2);
//$commonValue = 2
// If you have X number of arrays you can do:
$array1 = [1, 2];
$array2 = [2, 3, 4];
$arrayOfArrays = [$array1, $array2];
$commonValue = array_intersect(...$arrayOfArrays);

function getArraysIntersection(a1,a2){
    return  a1.filter(function(n) { return a2.indexOf(n) !== -1;});
}
var colors1 = ["red","blue","green"];
var colors2 = ["red","yellow","blue"];
var intersectingColors=getArraysIntersection(colors1, colors2); //["red", "blue"]