Set Operations in JavaScript

Using only vanilla JavaScript

> A = 'antonio'
> B = 'benito'
> A.split('')
[ 'a', 'n', 't', 'o', 'n', 'i', 'o' ]
> B.split('')
[ 'b', 'e', 'n', 'i', 't', 'o' ]
> AB = A.split('').concat(B.split(''))
[ 'a', 'n', 't', 'o', 'n', 'i', 'o', 'b', 'e', 'n', 'i', 't', 'o' ]
> uniqAB = A.split('')
    .concat(B.split('')
    .filter(x => A.split('').indexOf(x) < 0))
[ 'a', 'n', 't', 'o', 'n', 'i', 'o', 'b', 'e' ]
> intersectionAB = A.split('').filter(x => B.split('').includes(x))
[ 'n', 't', 'o', 'n', 'i', 'o' ]
> difference = A.split('').filter(x => !B.split('').includes(x))
[ 'a' ]
> symmetricDifferenceAB = A.split('')
    .filter(x => !B.split('').includes(x))
    .concat(B.split('').filter(x => !A.split('').includes(x)))
[ 'a', 'b', 'e' ]