如何给TypeScript中的一个JSON添加属性？

Question

我有以下代码：

type DailySummaryEntrry = {date: string, summary: ParsedSummary};

function parseDailySummaries (summaries: DailyRawSummaries): DailySummaryEntrry[] {
  const entries: DailySummaryEntrry[] = [];

  for (const date in summaries) {
    const rawSummary = summaries[date];
    if (!rawSummary) continue;
    entries.date = date ;
    entries.summary= parseRawSummary(rawSummary);
  }
  return entries.sort().reverse(); // sort by newest date first
}

我不知道为什么我得到

Property 'date' does not exist on type 'DailySummaryEntrry[]'.deno-ts(2339)

在这一行entries.date = date;

和：

Property 'summary' does not exist on type 'DailySummaryEntrry[]'.deno-ts(2339)

在这条线上

entries.summary= parseRawSummary(rawSummary);

Answer 1

在下面的for循环中：

  for (const date in summaries) {
    const rawSummary = summaries[date];
    if (!rawSummary) continue;
    entries.date = date ;
    entries.summary= parseRawSummary(rawSummary);
  }

entries是一个数组。 数组中不存在日期属性和摘要属性。 你可以做的是：

  for (const date in summaries) {
    const rawSummary = summaries[date];
    if (!rawSummary) continue;
    entries.push({date: date, summary: parseRawSummary(rawSummary)})
  }