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1. 数组去重 ​

js
let arr = [3, 5, 2, 2, 5, 5]; 
let setArr = new Set(arr)            // 返回set数据结构Set(3) {3, 5, 2} 
//方法一 es6的...解构 
let unique1 = [...setArr ];          //去重转数组后 [3,5,2] 
//方法二 Array.from()解析类数组为数组 
let unique2 = Array.from(setArr )    //去重转数组后 [3,5,2]
let arr = [3, 5, 2, 2, 5, 5]; 
let setArr = new Set(arr)            // 返回set数据结构Set(3) {3, 5, 2} 
//方法一 es6的...解构 
let unique1 = [...setArr ];          //去重转数组后 [3,5,2] 
//方法二 Array.from()解析类数组为数组 
let unique2 = Array.from(setArr )    //去重转数组后 [3,5,2]

2. 字符串去重 ​

js
let str = "352255"; 
let unique = [...new Set(str)].join(""); // 352
let str = "352255"; 
let unique = [...new Set(str)].join(""); // 352

3. 实现并集、交集、和差集 ​

js
let a = new Set([1, 2, 3]); 
let b = new Set([4, 3, 2]); 
// 并集 
let union = new Set([...a, ...b]); // Set {1, 2, 3, 4} 
// 交集 
let intersect = new Set([...a].filter(x => b.has(x))); // set {2, 3} 
// （a 相对于 b 的）差集 
let difference = new Set([...a].filter(x => !b.has(x))); // Set {1}
let a = new Set([1, 2, 3]); 
let b = new Set([4, 3, 2]); 
// 并集 
let union = new Set([...a, ...b]); // Set {1, 2, 3, 4} 
// 交集 
let intersect = new Set([...a].filter(x => b.has(x))); // set {2, 3} 
// （a 相对于 b 的）差集 
let difference = new Set([...a].filter(x => !b.has(x))); // Set {1}

4. 将伪数组转化为数组 ​

js
//伪数组转换为数组
var nodeList = document.querySelectorAll('div');
console.log([...nodeList]);  // [div, div, div ... ]
//伪数组转换为数组
var nodeList = document.querySelectorAll('div');
console.log([...nodeList]);  // [div, div, div ... ]

5. 配合rest 运算符应用 ​

js
function sumRest (...m) {
    var total = 0; 
    for(var i of m){
        total += i;
    }
    return total;
}
console.log(sumRest(1,2,3));//6
function sumRest (...m) {
    var total = 0; 
    for(var i of m){
        total += i;
    }
    return total;
}
console.log(sumRest(1,2,3));//6

6. 数组排序 ​

js
const sortNumbers = (...numbers) => numbers.sort();
const sortNumbers = (...numbers) => numbers.sort();