// 去重
const arr = [1, 2, 1, 3, 2]
const arr1 = [...new Set(arr)]
// 判断元素是否在集合中
const set = new Set(arr)
const has = set.has(2) // true
// 求交集
const set2 = new Set([2, 3])
const set3 = new Set([...set].filter(item => set2.has(item)))

// new
let mySet = new Set()
// add
mySet.add(1)
mySet.add(5)
mySet.add(5)
mySet.add('some text')
let o = { a: 1, b: 2 }
mySet.add(0)
mySet.add({ a: 1, b: 2 })
// has
mySet.has('some text')
// delete
mySet.delete(5)
// 迭代
for(let item of mySet) console.log(item)
for(let [key, value] of mySet.entries()) console.log(key, value)
// Set和Array转换
const myArr = [...mySet]
const myArr1 = Array.from(mySet)
const mySet2 = new Set([1,2,3,4])
// 交集
const intersection = new Set([...mySet].filter(x => mySet2.has(x)))
// 差集
const difference = new Set([...mySet]).filter(x => !mySet2.has(x))