let
a
=
new
Set
(
[
1
,
2
,
3
]
)
;
let
b
=
new
Set
(
[
4
,
3
,
2
]
)
;
// 并集
let
union
=
new
Set
(
[
.
.
.
a
,
.
.
.
b
]
)
;
// Set {1, 2, 3, 4}
// 交集
let
intersect
=
new
Set
(
[
.
.
.
a
]
.
filter
(
x
=
>
b
.
has
(
x
)
)
)
;
// set {2, 3}
// 差集
let
difference
=
new
Set
(
[
.
.
.
a
]
.
filter
(
x
=
>
!
b
.
has
(
x
)
)
)
;
// Set {1}