如何在JavaScript数组中移除重复的对象？

我有如下对象数组（已修正语法错误）：

[
  {teamName: 'first', playerId: 316},
  {teamName: 'first', playerId: 315},
  {teamName: 'first', playerId: 316},
  {teamName: 'first', playerId: 316},
  {teamName: 'second', playerId: 315},
  {teamName: 'second', playerId: 318},
  {teamName: 'third', playerId: 318},
  {teamName: 'third', playerId: 316}
]

需要编写函数移除数组中的重复对象（当teamName和playerId完全相同时视为重复项），输出结果如下：

[
  {teamName: 'first', playerId: 315},
  {teamName: 'first', playerId: 316},
  {teamName: 'second', playerId: 315},
  {teamName: 'second', playerId: 318},
  {teamName: 'third', playerId: 318},
  {teamName: 'third', playerId: 316}
]

解决方案 #

方法1：利用Set过滤重复项

将每个对象的teamName和playerId拼接成唯一字符串作为标识，通过Set记录已出现的标识，过滤掉重复项：

const removeDuplicates = (arr) => {
  const seenKeys = new Set();
  return arr.filter(item => {
    const uniqueKey = `${item.teamName}-${item.playerId}`;
    if (!seenKeys.has(uniqueKey)) {
      seenKeys.add(uniqueKey);
      return true;
    }
    return false;
  });
};

// 测试代码
const originalArr = [
  {teamName: 'first', playerId: 316},
  {teamName: 'first', playerId: 315},
  {teamName: 'first', playerId: 316},
  {teamName: 'first', playerId: 316},
  {teamName: 'second', playerId: 315},
  {teamName: 'second', playerId: 318},
  {teamName: 'third', playerId: 318},
  {teamName: 'third', playerId: 316}
];

console.log(removeDuplicates(originalArr));

方法2：使用reduce构建唯一集合

通过reduce将唯一标识作为键存储对象，最后提取对象值得到去重后的数组：

const removeDuplicates = (arr) => {
  const uniqueMap = arr.reduce((acc, item) => {
    const key = `${item.teamName}-${item.playerId}`;
    if (!acc[key]) acc[key] = item;
    return acc;
  }, {});
  return Object.values(uniqueMap);
};

// 测试代码同上

两种方法的核心逻辑一致：通过teamName与playerId的组合生成唯一标识，确保相同组合的对象仅保留一个。

内容的提问来源于stack exchange，提问作者fadsgas