Sorting JavaScript Object by property value

Question

If I have a JavaScript object such as:

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

Is there a way to sort the properties based on value? So that I end up with

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

Answer 1

This could be a simple way to handle it as a real ordered object. Not sure how slow it is. also might be better with a while loop.

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

}

And then I found this invert function from: 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)

Answer 2

Couln't find answer above that would both work and be SMALL, and would support nested objects (not arrays), so I wrote my own one :) Works both with strings and ints.

  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;
    }

Usage:

    /* 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'
       } 
    }

Answer 3

ECMAScript 2017 introduces Object.values / Object.entries. As the name suggests, the former aggregates all the values of an object into an array, and the latter does the whole object into an array of [key, value] arrays; Python's equivalent of dict.values() and dict.items().

The features make it pretty easier to sort any hash into an ordered object. As of now, only a small portion of JavaScript platforms support them, but you can try it on Firefox 47+.

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]]

Answer 4

I am following the solution given by slebetman (go read it for all the details), but adjusted, since your object is non-nested.

// First create the array of keys/values so that we can sort it:
var sort_array = [];
for (var key in list) {
    sort_array.push({key:key,value:list[key]});
}

// Now sort it:
sort_array.sort(function(x,y){return x.value - y.value});

// Now process that object with it:
for (var i=0;i<sort_array.length;i++) {
    var item = list[sort_array[i].key];

    // now do stuff with each item
}