javascript - 如何从对象列表中获取唯一值？

Question

数据:

[
  {
    "name": "Ankh of Anubis",
    "rank": {
      "_type": "medal",
      "current": "ankh-of-anubis"
    }
  },
  {
    "name": "Bonus Roulette",
    "rank": {
      "_type": "medal",
      "current": "bonus-roulette"
    }
  },
  {
    "name": "jetx",
    "rank": {
      "_type": "medal",
      "current": "jetx"
    }
  },
  {
    "name": "Gates of Olympus",
    "rank": {
      "_type": "trophy",
      "current": "gates-of-olympus"
    }
  },
]

如何只过滤唯一值，

uniqueValues = ["medal","trophy"]

我试过了，

1. const uniqueTitles = new Set(games.category.title);
2. const uniqueTitles = [...new Set(games.category.title)]//typescript 错误。

 useEffect(() => {
    const uniqueTitles = games.filter((game:any) => {
      return new Set(game.category.title);
    })
    setTitles(uniqueTitles);
  },[])

Answer 1

您正在使用 Set 作为过滤器函数的返回值。真的是这么打算的吗？给定数据:

const data = [
  {
    "name": "Ankh of Anubis",
    "rank": {
      "_type": "medal",
      "current": "ankh-of-anubis"
    }
  },
  {
    "name": "Bonus Roulette",
    "rank": {
      "_type": "medal",
      "current": "bonus-roulette"
    }
  },
  {
    "name": "jetx",
    "rank": {
      "_type": "medal",
      "current": "jetx"
    }
  },
  {
    "name": "Gates of Olympus",
    "rank": {
      "_type": "trophy",
      "current": "gates-of-olympus"
    }
  },
]

你可以这样做:

const uniqueValues = new Set();
data.forEach(record => uniqueValues.add(record.rank._type));
console.log(uniqueValues);

这是 link .