如何在JavaScript对象数组中找到重复值，并仅输出唯一值？ [英] How to find duplicate values in a JavaScript array of objects, and output only unique values?

问题描述

我正在学习JS。假设我有以下数组的对象：

  var family = [
 {
 name：Mike ，
 age：10 
}，
 {
 name：Matt
 age：13 
}，
 {
名称：Nancy，
年龄：15 
}，
 {
名称：Adam，
年龄：22 
}，
 {
名称：珍妮，
年龄：85 
}，
 {
名称：南希，
年龄：2 
}，
 {
 name：Carl，
 age：40 
} 
];请注意，南希显示两次（仅更改年龄）。假设我只输出唯一的名字。如何输出上述数组的对象，没有重复？ 
 
 
 
相关（找不到用于对象的好方法）：
 
 
 
 
 
 从JavaScript数组中删除重复数据< a> 
 
 
 在JavaScript数组中找到重复值的最简单的方法 
 
 
 
 
 
 编辑 。它对于字符串非常有效，但我无法确定如何使用对象：
  family.reduce（（a， b）=> {
 if（a.indexOf（b）< 0）{
 a.push（b）; 
} 
 return a; 
 }，[]）; 
  
 
 
解决方案
您可以使用 组合    Array＃map  和传播操作符  ...  
 
 
 
 Map返回一个包含所有名称的数组，正在进入设置的初始化程序，然后集合的所有值都返回一个数组。
 
 
 
 
 
 
  var family = [{name：Mike，age：10}，{name：Matt，age：13}，{name：Nancy年龄：15}，{名称：亚当，年龄：22}，{名称：珍妮，年龄：85}，{名称：南希，年龄：2}，{名称：卡尔 40}]，unique = [... new Set（family.map（a => a.name））]; console.log（unique）;  
 
 
 
 
 
 
为了过滤并返回唯一的名称，您可以使用  Array＃filter  与  Set  。
 
 
  var family = [{name：Mike，age：10}，{name：Matt，age：13}，{name：Nancy，age：15}，{name：Adam，age：22} {name：Jenny，age：85}，{name：Nancy，age：2}，{name：Carl，age：40}]，unique = family.filter（（set => f = >！set.has（f.name）&& set.add（f.name））（new Set））; console.log（unique）;  
 
 
 
 
I'm learning JS. Supposing I have the below array of objects:
var family = [
  {
    name: "Mike",
    age: 10
  },
  {
    name: "Matt"
    age: 13
  },
  {
    name: "Nancy",
    age: 15
  },
  {
    name: "Adam",
    age: 22
  },
  {
    name: "Jenny",
    age: 85
  },
  {
    name: "Nancy",
    age: 2
  },
  {
    name: "Carl",
    age: 40
  }
];
Notice that Nancy is showing up twice (changing only the age). Supposing I want to output only unique names. How do I output the above array of objects, without duplicates? ES6 answers more than welcome.

Related (couldn't find a good way for usage on objects):


Remove Duplicates from JavaScript Array
Easiest way to find duplicate values in a JavaScript array


EDIT Here's what I tried. It works well with strings but I can't figure how to make it work with objects:
family.reduce((a, b) => {
  if (a.indexOf(b) < 0 ) {
    a.push(b);
  }
  return a;
},[]);

解决方案
You could use a Set in combination with Array#map and a spread operator ... in a single line.

Map returns an array with all names, which are going into the set initializer and then all values of the set are returned in an array.



var family = [{ name: "Mike", age: 10 }, { name: "Matt", age: 13 }, { name: "Nancy", age: 15 }, { name: "Adam", age: 22 }, { name: "Jenny", age: 85 }, { name: "Nancy", age: 2 }, { name: "Carl", age: 40 }],
    unique = [...new Set(family.map(a => a.name))];

console.log(unique);





For filtering and return only unique names, you can use Array#filter with Set.


var family = [{ name: "Mike", age: 10 }, { name: "Matt", age: 13 }, { name: "Nancy", age: 15 }, { name: "Adam", age: 22 }, { name: "Jenny", age: 85 }, { name: "Nancy", age: 2 }, { name: "Carl", age: 40 }],
    unique = family.filter((set => f => !set.has(f.name) && set.add(f.name))(new Set));

console.log(unique);





                        
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