filtercondition2.js

let box1= ["juice", "sandwich", "chips", "yogurt"];

let box2 = ["milk", "sandwich", "carrots", "chips"];

let total = box1.concat(box2);

let answer = total.filter(function(item){
  
  //the items that are not included in box2 but are in total
  let justArr1 = !box2.includes(item);
  
  //the items that are not included in box1 but are in total
  let justArr2 = !box1.includes(item);
  
  return justArr1 || justArr2;
});