如何使用 js 数组方法（例如 map()、reduce()、filter() 等格式化来自服务器的响应，如下所示？

Question

This is the response object from an API that I need to reformat:

const data = {
  id: 12,
  currency: "USD",
  transactions: [
    {
      from_wallet_id: 14,
      transaction_amount: '30.00',
      type: 'income',
      "date": "2019-12-04T06:45:49.394000+06:00"
    },
    {
      from_wallet_id: 11,
      transaction_amount: '50.00',
      type: 'expenses',
      date: "2019-12-04T06:45:49.394000+06:00"
    },
    {
      from_wallet_id: 11,
      transaction_amount: '70.00',
      type: 'transfer',
      date: "2019-12-06T06:45:49.394000+06:00"
    },
    {
      from_wallet_id: 14,
      transaction_amount: '40.00',
      type: 'transfer',
      date: "2019-12-08T06:45:49.394000+06:00"
    },
  ]
}

I need to change it to the example given below (using array methods such as reduce, map, filter, etc) A little bit information: income is sum of transactions at that date. expenses is sum of transactions at that date. type "transfer" can be income or expense If type is "transfer" and from_wallet_id is not equals to data.id then it will be added to income otherwise it will be added to expenses

formattedObject = {
  "2019-12-04": {
    date: "2019-12-04",
    income: 30,
    expenses: 50
  },
  "2019-12-06": {
    date: "2019-12-06",
    income: 0,
    expenses: 70
  },
  "2019-12-08": {
    date: "2019-12-08",
    income: 40,
    expenses: 0
  }
}

Answer 1

You could reduce the array nad take an adjustment for type: 'transfer' .

 const data = { id: 12, currency: "USD", transactions: [{ from_wallet_id: 14, transaction_amount: '30.00', type: 'income', date: "2019-12-04T06:45:49.394000+06:00" }, { from_wallet_id: 11, transaction_amount: '50.00', type: 'expenses', date: "2019-12-04T06:45:49.394000+06:00" }, { from_wallet_id: 11, transaction_amount: '70.00', type: 'transfer', date: "2019-12-06T06:45:49.394000+06:00" }, { from_wallet_id: 14, transaction_amount: '40.00', type: 'transfer', date: "2019-12-08T06:45:49.394000+06:00" }] }, result = data.transactions.reduce((r, { from_wallet_id, transaction_amount, type, date }) => { date = date.slice(0, 10); if (type === 'transfer') type = data.id === from_wallet_id ? 'expenses' : 'income'; r[date] = r[date] || { date, income: 0, expenses: 0 }; r[date][type] += +transaction_amount; return r; }, {}); console.log(result);

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