手写数组的并集和交集

并集

let a = new Set([1,3,5])
let b = new Set([1,3,6])

let ab = new Set([...a, ...b])
// 输出 [1,3,5,6]

交集

let a = new Set([1,3,5])
let b = new Set([1,3,6])

let ab = new Set([...a].filter(x => b.has(x)))
// 输出 [1,3]