数组去重
let a = [1,2,3,4,4,5,6];
let b = [...new Set(a)]; // [1,2,3,4,5,6];
数组合并、去重
let arr1 = [1, 25, 2, 26, 1234, 6, 213];
let arr2 = [2, 6, 2134, 6, 31, 623];
let c = […new Set([…arr1, …arr2])].sort((a, b) => {
return a - b;
});