Question

如果我有一个对象数组

var bitcoinData = [
{
  "date": "2013-05-01",
  "txVolume(USD)": 108659660.293,
  "txCount": 52443,
  "marketcap(USD)": 1542820000,
  "price(USD)": 139,
  "exchangeVolume(USD)": 0,
  "generatedCoins": 3575,
  "fees": 36.80599998,
  "activeAddresses": null
},
{
  "date": "2013-05-02",
  "txVolume(USD)": 96958519.0041,
  "txCount": 55169,
  "marketcap(USD)": 1292190000,
  "price(USD)": 116.38,
  "exchangeVolume(USD)": 0,
  "generatedCoins": 3425,
  "fees": 54.40791613,
  "activeAddresses": null

如何使用map函数创建仅包含每天日期和价格的数组？

Answer 1

命名“ price（USD）”会导致销毁问题。所以用基本代替。给你。

const bitcoinData = [
{
  "date": "2013-05-01",
  "txVolume(USD)": 108659660.293,
  "txCount": 52443,
  "marketcap(USD)": 1542820000,
  "price(USD)": 139,
  "exchangeVolume(USD)": 0,
  "generatedCoins": 3575,
  "fees": 36.80599998,
  "activeAddresses": null
},
{
  "date": "2013-05-02",
  "txVolume(USD)": 96958519.0041,
  "txCount": 55169,
  "marketcap(USD)": 1292190000,
  "price(USD)": 116.38,
  "exchangeVolume(USD)": 0,
  "generatedCoins": 3425,
  "fees": 54.40791613,
  "activeAddresses": null
  }];
  
  const summary = bitcoinData.map(item => ({ date: item.date, price: item["price(USD)"] }));
  
  console.log(summary);

解决了破坏性问题，这里使用的是这种技术。

    const bitcoinData = [
    {
      "date": "2013-05-01",
      "txVolume(USD)": 108659660.293,
      "txCount": 52443,
      "marketcap(USD)": 1542820000,
      "price(USD)": 139,
      "exchangeVolume(USD)": 0,
      "generatedCoins": 3575,
      "fees": 36.80599998,
      "activeAddresses": null
    },
    {
      "date": "2013-05-02",
      "txVolume(USD)": 96958519.0041,
      "txCount": 55169,
      "marketcap(USD)": 1292190000,
      "price(USD)": 116.38,
      "exchangeVolume(USD)": 0,
      "generatedCoins": 3425,
      "fees": 54.40791613,
      "activeAddresses": null
      }];
      
      const summary = bitcoinData.map(({ date, "price(USD)": price }) => ({ date, price }));
      
      console.log(summary);

Answer 2

完成

var bitcoinData = [
{
  "date": "2013-05-01",
  "txVolume(USD)": 108659660.293,
  "txCount": 52443,
  "marketcap(USD)": 1542820000,
  "price(USD)": 139,
  "exchangeVolume(USD)": 0,
  "generatedCoins": 3575,
  "fees": 36.80599998,
  "activeAddresses": null
},
{
  "date": "2013-05-02",
  "txVolume(USD)": 96958519.0041,
  "txCount": 55169,
  "marketcap(USD)": 1292190000,
  "price(USD)": 116.38,
  "exchangeVolume(USD)": 0,
  "generatedCoins": 3425,
  "fees": 54.40791613,
  "activeAddresses": null
 }]
 
 console.log(bitcoinData.map(data=> {
 return {
   date: data.date,
   'price(USD)': data['price(USD)']
 }})
 )

Answer 3

尝试一下：

bitcoinData.map(element => {
    return ({"date":element.date, "price(USD)":element["price(USD)"]})
});

Answer 4

BitCoinData.map(bitCoin => {date: bitcoin.date, price: bitcoin.price});

这应该返回仅包含日期和价格的对象数组

如何使用map函数从对象数组返回多个键？ ES6

4 个答案: