Find missing element from 2nd Array

difference.js

function differenceFromSecondArray(arr1, arr2) {

  let arr1Map = arr1.reduce((acc, curr) => {
    return { ...acc, [curr]: 1 }
  }, {})

  return arr2.reduce((acc, curr) => arr1Map.hasOwnProperty(curr) ? acc : acc.concat(curr), [])
 
}