JSFiddle - React, Tailwind, and code Playground

JavaScript

/* jshint esversion: 6 */

function unique(value, index, self) { 
    return self.indexOf(value) === index;
}

function diff(a, b) {
  return a.filter(x => !b.includes(x));
}

function symdiff(a, b) {
  return [...diff(a, b), ...diff(b, a)].filter(unique);
}

function sym(...args) {
  return args.reduce(symdiff);
}

console.log(sym([1, 2, 3], [5, 2, 1, 4]));