Javascript合并具有相同属性的对象

Question

我有一个像这样的对象数组：

const arr = [
  {"id" : 1, "name" : "john", "age": 12, "fruits": "banana"},
  {"id" : 2, "name" : "john", "age": 12, "fruits": "apple"}
  {"id" : 3, "name" : "maria", "age": 13, "fruits": "grappes"}
  {"id" : 4, "name" : "maria", "age": 13, "fruits": "blackberry"}
  {"id" : 5, "name" : "camille", "age": 12, "fruits": "cherry"}
]

我想为每个人（名字）创建一个对象并添加他们的对象。

所以最终的数组将是：

const arr = [
  {"id" : 1, "name" : "john", "age": 12, "fruits": ["banana", "apple"]},
  {"id" : 3, "name" : "maria", "age": 13, "fruits": ["grappes", "blackberry"]}
  {"id" : 5, "name" : "camille", "age": 12, "fruits": ["cherry"]}
];

我使用的实际数组非常大，这就是为什么我正在寻找最有效的方法来做到这一点。

Answer 1

您可以使用Array.prototype.reduce对对象进行分组。

const arr = [
  { id: 1, name: "john", age: 12, fruits: "banana" },
  { id: 2, name: "john", age: 12, fruits: "apple" },
  { id: 3, name: "maria", age: 13, fruits: "grappes" },
  { id: 4, name: "maria", age: 13, fruits: "blackberry" },
  { id: 5, name: "camille", age: 12, fruits: "cherry" },
];

const output = Object.values(
  arr.reduce((res, o) => {
    if (!res[o.name]) {
      res[o.name] = { ...o, fruits: [] };
    }
    res[o.name].fruits.push(o.fruits);
    return res;
  }, {})
);

console.log(output);

您还可以将上面的解决方案写得更简洁：

const arr = [
  { id: 1, name: "john", age: 12, fruits: "banana" },
  { id: 2, name: "john", age: 12, fruits: "apple" },
  { id: 3, name: "maria", age: 13, fruits: "grappes" },
  { id: 4, name: "maria", age: 13, fruits: "blackberry" },
  { id: 5, name: "camille", age: 12, fruits: "cherry" },
];

const output = Object.values(
  arr.reduce(
    (res, o) => ((res[o.name] ||= { ...o, fruits: [] }).fruits.push(o.fruits), res),
    {}
  )
);

console.log(output);