javascript - 如何将对象数组重新映射到新数组中

Question

我有这个初始数组：

const initialData = [
  {
    day: 1,
    values: [
      {
        name: 'Roger',
        score: 90,
      },
      {
        name: 'Kevin',
        score: 88,
      },
      {
        name: 'Steve',
        score: 80,
      },
    ],
  },
  {
    day: 2,
    values: [
      {
        name: 'Roger',
        score: 70,
      },
      {
        name: 'Michael',
        score: 88,
      },
    ],
  },
  {
    day: 3,
    values: [
      {
        name: 'Steve',
        score: 97,
      },
    ],
  },
];

转换为：

const result = [
  {
    name: 'Roger',
    scores: [90, 70, null],
  },
  {
    name: 'Kevin',
    scores: [88, null, null],
  },
  {
    name: 'Steve',
    scores: [80, null, 97],
  },
  {
    name: 'Michael',
    scores: [null, 88, null],
  },
];

我正在尝试使用数组map并创建临时数组：

const holder = [];

initialData.map()

但无济于事

标签： javascripttypescriptecmascript-6

Answer 1

您可以通过几个步骤来执行此操作 - 首先reduce您可以按名称索引，然后将map这些条目设置为您期望的格式

const initialData = [{day:1,values:[{name:"Roger",score:90},{name:"Kevin",score:88},{name:"Steve",score:80}]},{day:2,values:[{name:"Roger",score:70},{name:"Michael",score:88}]},{day:3,values:[{name:"Steve",score:97}]}];


var result = Object.entries(initialData.reduce( (acc,item) => {
  item.values.forEach( v => {
    if(!acc[v.name]) acc[v.name] = {};
    acc[v.name][item.day] = v.score;
  });
  return acc;
},{})).map( ([name,days]) => ({  
    name,
    scores: new Array(initialData.length).fill(null).map( (_,i) => days[i+1] || null)
}))

console.log(result);