javascript 基于 ES6 中的单个项目对象数组组合对象数组

Question

我有以下数据

var data = [
  {username:'andy', entries:[{time_in:12, ..},{time_in:334,...}]},
  {username:'andy2', entries:[{time_in:'sr12', ..},{time_in:334,...}]}
]

我期待得到的是最终数据

var result = [
  {username:'andy', entry:12},
  {username:'andy', entry:334},
  {username:'andy2', entry:'sr12'},
  {username:'andy2', entry:334},
]

每个数组对象有更多属性，但为了简洁起见，我仅包含用户名

所以我已经尝试过

data.forEach(item=>{
  item.entries.forEach(entry=>{
    //am stuck here
  })
})

Answer 1

您可以将array#reduce与array#forEach结合使用。迭代每个对象，并为每个对象迭代 entries 数组，将新对象添加到累加器中。

const data = [
  {username: 'andy', entries: [{time_in: 12}, {time_in: 334}]},
  {username: 'andy2', entries: [{time_in: 'sr12'}, {time_in: 334}]}
]

const result = data.reduce((r, {username, entries}) => {
  entries.forEach(({time_in: entry}) => r.push({username, entry}))
  return r
}, [])

console.log(result)