Diff between two arrays

// gives array of diff between the two 
let difference = arr1
                 .filter(x => !arr2.includes(x))
                 .concat(arr2.filter(x => !arr1.includes(x)));


// separates the arrays so you know which array has which
  let difference1 = arr1.filter(x => !arr2.includes(x));               
  let difference2 = arr2.filter(x => !arr1.includes(x));