如何通过值[JS]获取对象的属性名称

Question

questions={
     1:{
          quest: "blah blah blah",
          answers: ["1812", "1837", "1864", "1899"],
          correct: "1837"
     },
     2:{
         quest: "fasfa asf",
         answers : ["2","3","4","5"],
         correct : "3"
     }
 }

例如，我知道1值。 我需要获取该对象的名称及其值。 var x = {quest: "blah blah blah", answers: ["1812", "1837", "1864", "1899"], correct: "1837"}

returnNameOf(x)预期输出1 ；

Answer 1

您可以在Object.keys() find()上使用find()并使用JSON.stringify()比较对象

 let questions={ 1:{ quest: "blah blah blah", answers: ["1812", "1837", "1864", "1899"], correct: "1837" }, 2:{ quest: "fasfa asf", answers : ["2","3","4","5"], correct : "3" } } let val = { quest: "fasfa asf", answers : ["2","3","4","5"], correct : "3" } function getKey(obj,value){ if(typeof value === "object"){ value = JSON.stringify(value); return Object.keys(obj).find(key => JSON.stringify(obj[key]) === value); } else return Object.keys(obj).find(key => obj[key] === value); } console.log(getKey(questions,val)); 

Answer 2

您可以将对象转换为字符串并进行比较。 因此，在此示例中，我们需要找到其值与toMatch匹配的键。 因此，在函数toMatch其转换为字符串，因为对象匹配或对象相等性测试在比较内存位置时将返回false

 let toMatch = { quest: "blah blah blah", answers: ["1812", "1837", "1864", "1899"], correct: "1837", }; let questions = { 1: { quest: "blah blah blah", answers: ["1812", "1837", "1864", "1899"], correct: "1837" }, 2: { quest: "fasfa asf", answers: ["2", "3", "4", "5"], correct: "3" } } function findKey(objString) { let val = JSON.stringify(toMatch) for (let keys in questions) { if (JSON.stringify(questions[keys]) === val) { return keys; } } } console.log(findKey(toMatch)) 

Answer 3

您可以在“对象”条目中搜索：

const key = 0, value = 1;

const result = Object.entries(questions).find(it => it[value] === x)[key];