Find uncommon values between two arrays

find.js

const firstArray = ['a', 'b', 'c', 'd', 'e'];
const secondArray = ['a', 'b', 'c', 'x', 'a', 'k', 'x','a','r'];

const acc = {};
const table = {};

function explore(val){
 if(val !== undefined && !acc[val]){
   table[val] = true;
 } else  if(val !== undefined) {
   delete table[val];
 }
  if(val !== undefined)
    acc[val] = true;
}

  (firstArray.length > secondArray.length 
	? firstArray 
    	: secondArray
  ).forEach((_, index) => {
	const first = firstArray[index];
	const second = secondArray[index];
	if(first !== second){
		explore(first);
		explore(second);
    }
  });
console.log(table);