const arr1 = [1,2,3,4,5],
arr2 = [5,6,7,8,9],
_arr1Set = new Set(arr1),
_arr2Set = new Set(arr2);
// 交集
let intersection = arr1.filter(item => _arr2Set.has(item))
// 并集
let union = Array.from(new Set([...arr1, ...arr2]))
// 补集 两个数组各自没有的集合
let complement = [...arr1.filter(item => !_arr2Set.has(item)), ...arr2.filter(item => !_arr1Set.has(item))]
// 差集 数组arr1相对于arr2所没有的
let diff = arr1.filter(item => !_arr2Set.has(item))
console.log('arr1: ', arr1);
console.log('arr2: ', arr2);
console.log('交集', intersection);
console.log('并集', union);
console.log('补集', complement);
console.log('差集', diff);
