JavaScript 去掉对象数组中key值相同的对象

Question

题目描述

去掉对象数组中key值相同的对象

题目来源及自己的思路

相关代码

let arr = [
  {"weight":10,"id":1},
  {"weight":20,"id":2},
  {"weight":30,"id":2},
  {"weight":40,"id":4},
  {"weight":50,"id":5}
];

你期待的结果是什么？实际看到的错误信息又是什么？

let arr = [
  {"weight":10,"id":1},
  {"weight":30,"id":2},
  {"weight":40,"id":4},
  {"weight":50,"id":5}
];

Answer 1

let obj = {}
arr = arr.reduce((item, next) => {
  obj[next.id] ? '' : obj[next.id] = true && item.push(next)
  return item
}, [])
console.log(arr)

Answer 2

用工具函数吧，lodash uniqBy,

const arr = [
  {"weight":10,"id":1},
  {"weight":20,"id":2},
  {"weight":30,"id":2},
  {"weight":40,"id":4},
  {"weight":50,"id":5}
]
_.uniqBy(arr, 'id')

Answer 3

如果按照提供的参考结果，id为“2”的数据出现了两次，取的其实是后一次的值，那么上面的答案是不对的。

let obj = {}
arr.map(item => {
  obj[item.id] = item
})
let result = Object.values(obj)

Answer 4

不要忘了楼主本身的数据是用数组存储的，而数组本身就是有序的，而对象key却是无序的。所以使用原生对象key去重的都不是最符合要求的答案。这里给个可能的答案

[...new Map(arr.map(({id, weight})=>([id, weight]))).entries()].map(([id, weight])=>({id, weight}))