1. 定义set

let manage_ip = new Set();
manage_ip.add(1)
manage_ip.add(1)
manage_ip.add(2)
manage_ip.add(2)
manage_ip.add(3)
manage_ip.add(4)
console.log(manage_ip.size);

// 或者
let manage_ip = new Set([1,2,3,4,4,]);

2. set 与 数组 相互转换

2.1 array --> set (数组转set)

let array = [1, 2, 3, 4];
let set = new Set(array);

2.2 set --> array (使用Array.from()方法)

let demo = new Set([1,2,3,4]);
Array.from(demo)