数据结构
网络
关系型数据库管理系统
操作系统
Java
MS Excel
iOS
HTML
CSS
Android
Python
C 语言编程
C++
C#
MongoDB
MySQL
JavaScript
PHP
物理
化学
生物学
数学
英语
经济学
心理学
社会科学
时装研究
法律研究复杂的 JavaScript 数组分组
假设我们有一个如下所示的对象数组 -
const arr = [
{userId: "3t5bsFB4PJmA3oTnm", from: 1, to: 6},
{userId: "3t5bsFB4PJmA3oTnm", from: 7, to: 15},
{userId: "3t5bsFB4PJmA3oTnm", from: 172, to: 181},
{userId: "3t5bsFB4PJmA3oTnm", from: 182, to: 190}
];我们要求编写一个 JavaScript 函数，该函数取入这样的一个数组。该函数应根据 “from” 和 “to” 属性将重叠的对象分组到一个对象中，如下所示 -
const output = [
{userId: "3t5bsFB4PJmA3oTnm", from: 1, to: 15},
{userId: "3t5bsFB4PJmA3oTnm", from: 172, to: 190}
];示例
const arr = [
{userId: "3t5bsFB4PJmA3oTnm", from: 1, to: 6},
{userId: "3t5bsFB4PJmA3oTnm", from: 7, to: 15},
{userId: "3t5bsFB4PJmA3oTnm", from: 172, to: 181},
{userId: "3t5bsFB4PJmA3oTnm", from: 182, to: 190}
];
const groupByDuration = (arr = []) => {
const result = arr.reduce((acc, val) => {
let last = acc[acc.length - 1] || {};
if (last.userId === val.userId && last.to + 1 === val.from) {
last.to = val.to; } else {
acc.push({ userId: val.userId, from: val.from, to: val.to });
}
return acc;
}, []);
return result;
}
console.log(groupByDuration(arr));输出
控制台中的输出为 -
[
{ userId: '3t5bsFB4PJmA3oTnm', from: 1, to: 15 },
{ userId: '3t5bsFB4PJmA3oTnm', from: 172, to: 190 }
]
更新于: 2020-11-21
148 次浏览
广告