how to overlap arrays code example

Example 1: javascript do arrays intersect

let intersection = arrA.filter(x => arrB.includes(x));

Example 2: javascript get intersection of two arrays

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"]