Array.prototype.reduce()方法介绍: 感性认识reduce累加器: const arr = [1, 2, 3, 4]; const reducer = (accumulator, currentValue) => accumulator + currentValue; console.log(arr.reduce(reducer)): //10,即1 + 2 + 3 + 4. console.log(arr.reduce(reducer, 6))://16,即6 + 1 +…

es6方法: 普通数组: 1.使用Array.from(new Set(arr)); /* * @param oldArr 带有重复项的旧数组 * @param newArr 去除重复项之后的新数组 * */ let oldArr = [1, 1, 1, 2, 3, 2, 4, 4, 4, 9, 9, 0, 0, NaN, NaN]; let newArr = Array.from(new Set(oldArr)); console.log(newArr); // [1, 2, 3, 4, 9,…

JS数组去重 JS中对数组去重最好不要用unique方法,该方法主要是对dom节点数组的去重,如果对普通的数组元素去重只会去掉与之相邻的重复元素,也就是如果数组中还有不相邻的重复元素存在,将不会被去掉,而且有时候会出现问题,所以对数组去重可以利用如下方法: 先对数组a进行遍历,同时创建一个新的数组对象arr for (var i=0 ;i<a.length;i++) {    if (arr.indexOf(a[i]) == -1) { arr.push(a[i]) } } 经过这样处理后的数组…

简单的数组去重是比较简单的,方法也特别多,如给下面的数组去重: let arr = [1,2,2,4,9,6,7,5,2,3,5,6,5] 最常用的可以用for循环套for循环,再用splice删除重复的数组: let arrUnique = function (arr){ for(let i=0; i<arr.length; i++){ for(let j=i+1; j<arr.length; j++){ if(arr[i]==arr[j]){ //第一个等同于第二个,splice方法删除第…

直接修改数组元素是无法触发视图更新的,如 this.array[0] = { name: 'meng', age: 22 } 修改array的length也无法触发视图更新,如 this.array.length = 2; 触发视图更新的方法有如下几种 1. Vue.set 可以设置对象或数组的值,通过key或数组索引,可以触发视图更新 数组修改 Vue.set(array, indexOfItem, newValue) this.array.$set(indexOfItem, newValue…

let log = console.log.bind(console); let person = [ {id: 0, name: "小明"}, {id: 1, name: "小张"}, {id: 2, name: "小李"}, {id: 3, name: "小孙"}, {id: 1, name: "小周"}, {id: 2, name: "小陈"}, ]; let obj = {};…

转: https://www.cnblogs.com/gaoht/p/9850449.html 在数组对象中去掉重复的对象: export function deteleObject(obj) { var uniques = []; var stringify = {}; for (var i = 0; i < obj.length; i++) { var keys = Object.keys(obj[i]); keys.sort(function(a, b) { return (Number(…

var arr = [{ key: '01', value: '乐乐' }, { key: '02', value: '博博' }, { key: '03', value: '淘淘' },{ key: '04', value: '哈哈' },{ key: '01', value: '乐乐' }]; // 方法1:利用对象访问属性的方法,判断对象中是否存在key var result = []; var obj = {}; for(var i =0; i<arr.length; i++){ if(…

let hash = {}; let config = [ { name: 2, state: true, output: 'Y'}, { name: 3, state: true, output: 'A'}, { name: 5, state: true, output: 'S'}, { name: 7, state: true, output: 'B'} ]; config = [...config, { // 合并数组 ...运算符即为数组展开运算符 name: 3, state: fal…

var Arrlist = [ {name:"张三",age:25,time:"2018-07-30 17:45:13"}, {name:"赵六",age:18,time:"2018-07-26 11:10:30"}, {name:"李四",age:28,time:"2018-07-30 16:53:27"}, {name:"王五",age:999,time:&quo…