在JavaScript中查找数组中具有重复名称的对象

Question

我有一个数组，我在searchName节中找到，在resultName节中，我分离了重复的名称，在filters节中，我想显示在console.log中具有这些重复名称的对象，但一个空数组请帮助我得到答案

const data = [
{id: 1,name: "Liam",age: 20},
{id: 1,name: "Noah",age: 22},
{id: 1,name: "Liam",age: 20},
{id: 1,name: "Elijah",age: 18},
{id: 1,name: "Elijah",age: 18}
]
const searchName = data.map(item => item.name)
console.log(searchName);
const toFindDuplicates = arry => arry.filter((item, index) => arry.indexOf(item) !== index);
const resultName = toFindDuplicates(searchName)
console.log(resultName);
const filters = data.filter(x => x.Name === resultName)
console.log(filters);

Answer 1

使用.includes()检查元素的名称是否存在于resultName数组中。您还有一个错别字:x.name而不是x.Name

const data = [{
id: 1,
name: "Liam",
age: 20
},
{
id: 1,
name: "Noah",
age: 22
},
{
id: 1,
name: "Liam",
age: 20
},
{
id: 1,
name: "Elijah",
age: 18
},
{
id: 1,
name: "Elijah",
age: 18
}
]
const searchName = data.map(item => item.name)
console.log(searchName);
const toFindDuplicates = arry => arry.filter((item, index) => arry.indexOf(item) !== index);
const resultName = toFindDuplicates(searchName)
console.log(resultName);
const filters = data.filter(x => resultName.includes(x.name))
console.log(filters);

Answer 2

你需要修正你的过滤器功能。

在您的版本中，您试图将数组与字符串进行比较。

你需要做的是像这样:

const filters = data.filter(x => resultName.includes(x.name))

Answer 3

首先可以数名字，然后填充数组

const data = [
{id: 1,name: "Liam",age: 20},
{id: 1,name: "Noah",age: 22},
{id: 1,name: "Liam",age: 20},
{id: 1,name: "Elijah",age: 18},
{id: 1,name: "Elijah",age: 18}
]
const obj = data.reduce((acc, el) => { acc[el.name] = (acc[el.name] ?? 0) + 1; return acc; }, {});
const all = Object.keys(obj);
const duplicates = Object.entries(obj).filter(el => el[1] > 1).map(el => el[0]);
const uniques = Object.entries(obj).filter(el => el[1] === 1).map(el => el[0]);
console.log(all);
console.log(duplicates);
console.log(uniques);