javascript - 无法减少数组中相关的 JavaScript 对象

Question

我正在尝试按键将相关的 JavaScript 对象分组到数组中。

但是，我陷入了困境。

我有一个像这样的 JavaScript 对象数组:

[
    {
        "text": "hello world",
        "startPos": 0,
        "endPos": 12,
        "value": "hello world",
        "entity": "Greeting"
    },
    {
        "text": "hello world",
        "startPos": 0,
        "endPos": 6,
        "value": "hello",
        "entity": "Greeting"
    }
]

我编写了以下代码，但我被卡住了。

a = [
  {
    "text": "hello world",
    "startPos": 0,
    "endPos": 12,
    "value": "hello world",
    "entity": "Greeting"
  },
  {
    "text": "hello world",
    "startPos": 0,
    "endPos": 6,
    "value": "hello",
    "entity": "Greeting"
  }
]

let result = a.reduce((acc, d) => {
  const found = acc.find(a => a.text == d.text);
  const entitiesArray = {
    startPos: d.startPos,
    endPos: d.endPos,
    entity: d.entity
  };
  if (found) {
    found.entities.push(entitiesArray);
  } else {
    acc.push({});
  }
  return acc;
}, []);

console.log(JSON.stringify(result, undefined, 4));

JavaScript 对象根据“text” 键重复。我想根据 "text" 键将上述数组分组为一个对象。

类似这样的事情:

[
    {
        "text": "hello world",
        "entities": [
                {
                    "startPos": 0,
                    "endPos": 12,
                    "value": "hello world",
                    "entity": "Greeting"
                },
                {
                    "startPos": 0,
                    "endPos": 6,
                    "value": "hello",
                    "entity": "Greeting"
                }
        ]
    }
]

Answer 1

当 found 为 false 时，您错过了将带有 text 的对象添加到数组中。因此，在接下来的迭代中，它无法找到比较文本的对象

此外，如果您的 IDE 和引擎支持新的 ES 提案，您可以使用 Rest/Spread Properties

const a = [
  {
    "text": "hello world",
    "startPos": 0,
    "endPos": 12,
    "value": "hello world",
    "entity": "Greeting"
  },
  {
    "text": "hello world",
    "startPos": 0,
    "endPos": 6,
    "value": "hello",
    "entity": "Greeting"
  }
]

let result = a.reduce((acc, d) => {
  const found = acc.find(a => a.text == d.text);
  
  const { text, ...entitiesArray } = { ...d }; // <- Rest/Spread properties
  
  found ? found.entities.push(entitiesArray) 
        : acc.push({ text: d.text, entities: [entitiesArray]})

  return acc;
}, []);

console.log(result);