从数组键中获取值并构建一个新数组

Question

我无法获取“日期”键的值来构建我的数组。const input = [{  "Date": "12/08/2020",  "Day": "Wednesday"}, {  "Date": "13/08/2020",  "Day": "Thursday"}, {  "Date": "14/08/2020",  "Day": "Friday"}];function get(o, days) {  const weekdays = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];  const [dd, mm, yyyy] = Object.keys(o)[0].split('/');  const date = new Date(`${yyyy}-${mm}-${dd}`);  date.setUTCDate(date.getUTCDate() + days);  const key = `${    `${date.getUTCDate()}`.padStart(2, '0')    }/${    `${(date.getUTCMonth() + 1)}`.padStart(2, '0')    }/${    date.getUTCFullYear()    }`;  const value = weekdays[date.getUTCDay()];  return {    [key]: value  };}function prepend(array, count) {  while (count-- > 0) {    array.unshift(get(input[0], -1));  }}function append(array, count) {  while (count-- > 0) {    array.push(get(input[input.length - 1], 1));  }}prepend(input, 1);append(input, 1);console.log(input);控制台显示此输出：{NaN/NaN/NaN: undefined},{Date: "12/08/2020", Day: "Wednesday"},{Date: "13/08/2020", Day: "Thursday"},{Date: "14/08/2020", Day: "Friday"},{NaN/NaN/NaN: undefined}似乎问题出在Object.keys(o)[0]. 我怎样才能解决这个问题？

Answer 1

您实际上想要第一个值，而不是第一个键。

const [dd, mm, yyyy] = Object.values(o)[0].split('/');

但是，由于您已经知道密钥的名称，您可以简单地使用o.Date.

const [dd, mm, yyyy] = o.Date.split('/');