js 两个数组对比，去除相同项得到新数组

var arr1 = [a, b, c,];
var arr2 = [a, b, c, d];
let list = arr2.filter(items => {
  if (!arr1.includes(items)) return items;
})
console.log(list);var arr1 = [a, b, c,];
var arr2 = [a,