使用Underscore.js库:

var hash = {
  foo: 1,
  bar: 2
};

(_.invert(hash))[1]; // => 'foo'

http://jsfiddle.net/rTazZ/2/

var a = new Array(); 
    a.push({"1": "apple", "2": "banana"}); 
    a.push({"3": "coconut", "4": "mango"});

    GetIndexByValue(a, "coconut");

    function GetIndexByValue(arrayName, value) {  
    var keyName = "";
    var index = -1;
    for (var i = 0; i < arrayName.length; i++) { 
       var obj = arrayName[i]; 
            for (var key in obj) {          
                if (obj[key] == value) { 
                    keyName = key; 
                    index = i;
                } 
            } 
        }
        //console.log(index); 
        return index;
    } 

Non-iteratable解决方案

主要功能:

var keyByValue = function(value) {

    var kArray = Object.keys(greetings);        // Creating array of keys
    var vArray = Object.values(greetings);      // Creating array of values
    var vIndex = vArray.indexOf(value);         // Finding value index 

    return kArray[vIndex];                      // Returning key by value index
}

对象的键和值:

var greetings = {
    english   : "hello",
    ukranian  : "привіт"
};

测试:

keyByValue("привіт");
// => "ukranian"

给定输入={"a":"x"， "b":"y"， "c":"x"}…

使用第一个值(如输出={“x”:“一”,“y”:“b”}):

输入= { “一个”:“x”, “b”:“y”, “c”:“x” ｝ output = Object.keys(input)。reduceRight(函数(accum, key, i) { Accum [input[key]] = key; 返回accum; }, {}) console.log(输出)

使用最后一个值(例如输出={“x”:“c”、“y”:“b”}):

输入= { “一个”:“x”, “b”:“y”, “c”:“x” ｝ output = Object.keys(input)。Reduce(函数(accum, key, i) { Accum [input[key]] = key; 返回accum; }, {}) console.log(输出)

为每个值数组的键(例如输出={“x”:“c”,“a”,“y”:[b]}):

输入= { “一个”:“x”, “b”:“y”, “c”:“x” ｝ output = Object.keys(input)。reduceRight(函数(accum, key, i) { accum[输入[主要]]= (accum[输入[键 ]] || []). concat(关键); 返回accum; }, {}) console.log(输出)

下划线js解决方案

let samplLst = [{id:1,title:Lorem},{id:2,title:Ipsum}]
let sampleKey = _.findLastIndex(samplLst,{_id:2});
//result would be 1
console.log(samplLst[sampleKey])
//output - {id:2,title:Ipsum}

lodash way https://lodash.com/docs#findKey

Var用户= { 'barney':{'年龄':36，'活跃':true}， 'fred': {'age': 40， 'active': false}， '鹅卵石':{'年龄':1，'活动':true} }; _。findKey(users， {'age': 1， 'active': true}); //→'鹅卵石'