从对象数组中获取唯一值

Question

我有一个像这样的动态对象数组:

var arr = [
    {state: "FL"},
    {state: "NY"},
    {state: "FL"},
    {gender: "Male"},
    {state: "NY"},
    {gender: "Female"},
    {gender: "Female"},
    {year: "1990"}
]

我怎样才能获得独特的物体？

所需的输出是一个只包含唯一对象的数组:

arr = [
    {state: "FL"},
    {state: "NY"},
    {gender: "Male"},
    {gender: "Female"},
    {year: "1990"}
]

我正在尝试使用reduce这样的东西,但在这种方式我需要知道对象键:

arr = arr.reduce((acc, curr) => 
    acc.find(e => e['state'] === curr['state']) ? acc : [...acc, curr], [])

这不是重复,因为其他问题不使用"动态对象"来获得独特性

Answer 1

您可以对所有对象进行字符串化,获取唯一的JSON并将字符串转换回对象.

var array = [{ state: "FL" }, { state: "NY" }, { state: "FL" }, { gender: "Male" }, { state: "NY" }, { gender: "Female" }, { gender: "Female" }, { year: "1990" }],
    unique = Array.from(
        new Set(array.map(o => JSON.stringify(o))),
        s => JSON.parse(s)
    );
    
console.log(unique);

.as-console-wrapper { max-height: 100% !important; top: 0; }

如果对象中有多个键,并且因为如果对象的键不同,我建议首先获取条目,对此数组进行排序,将其字符串化为一组并返回新对象.

var array = [{ foo: 42, state: "FL" }, { state: "FL", foo: 42 }, { state: "FL" }, { state: "NY" }, { state: "FL" }, { gender: "Male" }, { state: "NY" }, { gender: "Female" }, { gender: "Female" }, { year: "1990" }],
    unique = Array.from(
        new Set(array.map(o => JSON.stringify(Object.entries(o).sort(([a], [b]) => a.localeCompare(b))))),
        s => Object.assign({}, ...JSON.parse(s).map(([k, v]) => ({ [k]: v })))
    );
    
console.log(unique);

.as-console-wrapper { max-height: 100% !important; top: 0; }