let intersection = a.filter(v => b.includes(v)) 返回交集数组
let difference = a.concat(b).filter(v => !a.includes(v) || !b.includes(v)) 返回相差元素数组
let intersection = a.filter(v => b.includes(v)) 返回交集数组
let difference = a.concat(b).filter(v => !a.includes(v) || !b.includes(v)) 返回相差元素数组