如果我有一个JavaScript对象,如:

var list = {
  "you": 100, 
  "me": 75, 
  "foo": 116, 
  "bar": 15
};

是否有一种方法可以根据值对属性进行排序?最后得到

list = {
  "bar": 15, 
  "me": 75, 
  "you": 100, 
  "foo": 116
};

当前回答

这可能是一种将其作为真实有序对象处理的简单方法。不知道它有多慢。也可能更好的while循环。

Object.sortByKeys = function(myObj){
  var keys = Object.keys(myObj)
  keys.sort()
  var sortedObject = Object()
  for(i in keys){
    key = keys[i]
    sortedObject[key]=myObj[key]
   }

  return sortedObject

}

然后我找到了这个逆函数 http://nelsonwells.net/2011/10/swap-object-key-and-values-in-javascript/

Object.invert = function (obj) {

  var new_obj = {};

  for (var prop in obj) {
    if(obj.hasOwnProperty(prop)) {
      new_obj[obj[prop]] = prop;
    }
  }

  return new_obj;
};

So

var list = {"you": 100, "me": 75, "foo": 116, "bar": 15};
var invertedList = Object.invert(list)
var invertedOrderedList = Object.sortByKeys(invertedList)
var orderedList = Object.invert(invertedOrderedList)

其他回答

ECMAScript 2017引入了Object。values / Object.entries。顾名思义,前者将一个对象的所有值聚合到一个数组中,后者将整个对象聚合到一个[key, value]数组数组中;Python等价于dict.values()和dict.items()。

这些特性使得将任何散列排序到有序对象中变得非常容易。到目前为止,只有一小部分JavaScript平台支持它们,但您可以在Firefox 47+上尝试一下。

编辑:现在所有现代浏览器都支持!

let obj = {"you": 100, "me": 75, "foo": 116, "bar": 15};

let entries = Object.entries(obj);
// [["you",100],["me",75],["foo",116],["bar",15]]

let sorted = entries.sort((a, b) => a[1] - b[1]);
// [["bar",15],["me",75],["you",100],["foo",116]]

我已经用自己的方式尝试过了

var maxSpeed = {
  car: 300, 
  bike: 60, 
  motorbike: 200, 
  airplane: 1000,
  helicopter: 400, 
  rocket: 8 * 60 * 60
};
var sorted = {}
 Object.keys(maxSpeed).sort ((a,b) => maxSpeed[a] - maxSpeed[b]).map(item => sorted[item] = maxSpeed[item]);
console.log(sorted)

找不到上面的答案,既工作又小,并支持嵌套对象(不是数组),所以我写了自己的一个:)工作与字符串和整数。

  function sortObjectProperties(obj, sortValue){
      var keysSorted = Object.keys(obj).sort(function(a,b){return obj[a][sortValue]-obj[b][sortValue]});
      var objSorted = {};
      for(var i = 0; i < keysSorted.length; i++){
          objSorted[keysSorted[i]] = obj[keysSorted[i]];
      }
      return objSorted;
    }

用法:

    /* sample object with unsorder properties, that we want to sort by 
    their "customValue" property */

    var objUnsorted = {
       prop1 : {
          customValue : 'ZZ'
       },
       prop2 : {
          customValue : 'AA'
       }
    }

    // call the function, passing object and property with it should be sorted out
    var objSorted = sortObjectProperties(objUnsorted, 'customValue');

    // now console.log(objSorted) will return:
    { 
       prop2 : {
          customValue : 'AA'
       },
       prop1 : {
          customValue : 'ZZ'
       } 
    }

输入是对象,输出是对象,使用lodash & js内置库,降序或升序选项,不改变输入对象

Eg输入输出

{
  "a": 1,
  "b": 4,
  "c": 0,
  "d": 2
}
{
  "b": 4,
  "d": 2,
  "a": 1,
  "c": 0
}

实现

const _ = require('lodash');

const o = { a: 1, b: 4, c: 0, d: 2 };


function sortByValue(object, descending = true) {
  const { max, min } = Math;
  const selector = descending ? max : min;

  const objects = [];
  const cloned = _.clone(object);

  while (!_.isEmpty(cloned)) {
    const selectedValue = selector(...Object.values(cloned));
    const [key, value] = Object.entries(cloned).find(([, value]) => value === selectedValue);

    objects.push({ [key]: value });
    delete cloned[key];
  }

  return _.merge(...objects);
}

const o2 = sortByValue(o);
console.log(JSON.stringify(o2, null, 2));

对象按值排序(DESC)

function sortObject(list) {
  var sortable = [];
  for (var key in list) {
    sortable.push([key, list[key]]);
  }

  sortable.sort(function(a, b) {
    return (a[1] > b[1] ? -1 : (a[1] < b[1] ? 1 : 0));
  });

  var orderedList = {};
  for (var i = 0; i < sortable.length; i++) {
    orderedList[sortable[i][0]] = sortable[i][1];
  }

  return orderedList;
}