javascript - 从对象数组返回名称数组

Question

我知道如何循环访问一个对象并打印出我想要的值数组，但我无法按照我想要的顺序打印它。

**问题是:**

给定一组游戏结果记录，通过返回姓名数组来确定所有玩家是谁。

数组应按名称的出现方式排序。

输入示例:

[
  { winner: 'Alishah', loser: 'Bob',    loser_points: 3 },
  { winner: 'Maria',   loser: 'Xu Jin', loser_points: 1 },
  { winner: 'Elise',   loser: 'Bob',    loser_points: 2 },
  { winner: 'Elise',   loser: 'Maria',  loser_points: 4 },
  { winner: 'Alishah', loser: 'Maria',  loser_points: 2 },
  { winner: 'Maria',   loser: 'Xu Jin', loser_points: 3 },
  { winner: 'Xu Jin',  loser: 'Elise',  loser_points: 2 }
]

预期结果:

['艾莉莎', '鲍勃', '玛丽亚', '徐进', '伊莉丝']

**我到目前为止的代码:**

let data = [
  { winner: 'Alishah', loser: 'Bob',    loser_points: 3 },
  { winner: 'Maria',   loser: 'Xu Jin', loser_points: 1 },
  { winner: 'Elise',   loser: 'Bob',    loser_points: 2 },
  { winner: 'Elise',   loser: 'Maria',  loser_points: 4 },
  { winner: 'Alishah', loser: 'Maria',  loser_points: 2 },
  { winner: 'Maria',   loser: 'Xu Jin', loser_points: 3 },
  { winner: 'Xu Jin',  loser: 'Elise',  loser_points: 2 }
];

   
console.log(main(data));

Answer 1

您可以使用.flatMap()和 Set()为此:

let data = [
  { winner: 'Alishah', loser: 'Bob',    loser_points: 3 },
  { winner: 'Maria',   loser: 'Xu Jin', loser_points: 1 },
  { winner: 'Elise',   loser: 'Bob',    loser_points: 2 },
  { winner: 'Elise',   loser: 'Maria',  loser_points: 4 },
  { winner: 'Alishah', loser: 'Maria',  loser_points: 2 },
  { winner: 'Maria',   loser: 'Xu Jin', loser_points: 3 },
  { winner: 'Xu Jin',  loser: 'Elise',  loser_points: 2 }
];

const res = [...new Set(data.flatMap(x=>[x.winner, x.loser]))]
console.log( res )

说明:

• 使用.flatMap()方法我们首先会得到一个数组的数组。这里的内部数组将是 winner 和 loser 名称的数组。
• 然后我们将展平数组以获得所有玩家姓名的单个数组。
• 最后使用[...new Set(array)]我们将在数组中获得不同的名称以实现所需的结果。