array intersection in js code example

Example 1: javascript do arrays intersect

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

Example 2: js array intersection object

const arr1 = [{ id: 1 }, { id: 2 }]
const arr2 = [{ id: 1 }, { id: 3 }]
const intersection = arr1.filter(item1 => arr2.some(item2 => item1.id === item2.id))
// intersection => [{ id: 1 }]

Example 3: 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"]

Example 4: array intersection javascript es6

const intersection = (a, b) => {
  b = new Set(b); // recycling variable
  return [...new Set(a)].filter(e => b.has(e));
};

console.log(intersection([1, 2, 3, 1, 1], [1, 2, 4])); // Array [ 1, 2 ]