Diff Two Arrays challenge feedback

Hi people,

Just thought I’d post my code for the Diff Two Arrays challenge, it takes advantage of Sets so the nice has() method can be used. However how can I improve this? I feel like 2 for loops doing roughly the same thing is slightly inefficient.

/* jshint esversion: 6 */
function diffArray(arr1, arr2) {
  const filteredSet = new Set();
  const set1 = new Set(arr1);
  const set2 = new Set(arr2);
 
  for(let item of set1) {
    if(set2.has(item)) {
      continue;
    } else {
     filteredSet.add(item);
    }
  }
  
  for(let item of set2) {
   if(set1.has(item)) {
    continue; 
   } else {
    filteredSet.add(item); 
   }
  }
  
  const newArray = Array.from(filteredSet);
  return newArray;
}

diffArray([1, 2, 3, 5, 7, "test string"], [1, 2, 3, 4, 5]);

Some guidance on how to improve this would be great!

Thanks!
James.