javascript - 循环多个数组并对相同键的值求和

Question

我有多个不同长度的数组，每个数组都有键值对的对象。

[{date: "2018-11-26", totalHours: 2},{date: "2018-11-27", totalHours: 2}]
[{date: "2018-11-26", totalHours: 4},{date: "2018-11-27", totalHours: 2},{date: "2018-11-28", totalHours: 8}]
[{date: "2018-11-26", totalHours: 4},{date: "2018-11-27", totalHours: 2},{date: "2018-11-28", totalHours: 6},{date: "2018-11-30", totalHours: 9}]

考虑到所有数组，如何求和相同日期的总时间？

标签： javascriptreactjs

Answer 1

您可以按如下方式使用reduce函数：

const x = [{ date: '2018-11-26', totalHours: 2 }, { date: '2018-11-27', totalHours: 2 }]

const sum = x.reduce((a, c) => a + c.totalHours, 0)
console.log(sum) // 4