Sorting JavaScript Object by property value

Sorting JavaScript Object by property value

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
};

Solutions/Answers:

Solution 1:

Move them to an array, sort that array, and then use that array for your purposes. Here’s a solution:

var maxSpeed = {
    car: 300, 
    bike: 60, 
    motorbike: 200, 
    airplane: 1000,
    helicopter: 400, 
    rocket: 8 * 60 * 60
};
var sortable = [];
for (var vehicle in maxSpeed) {
    sortable.push([vehicle, maxSpeed[vehicle]]);
}

sortable.sort(function(a, b) {
    return a[1] - b[1];
});

//[["bike", 60], ["motorbike", 200], ["car", 300],
//["helicopter", 400], ["airplane", 1000], ["rocket", 28800]]

Once you have the array, you could rebuild the object from the array in the order you like, thus achieving exactly what you set out to do. That would work in all the browsers I know of, but it would be dependent on an implementation quirk, and could break at any time. You should never make assumptions about the order of elements in a JavaScript object.

Solution 2:

We don’t want to duplicate the entire data structure, or use an array where we need an associative array.

Here’s another way to do the same thing as bonna:

var list = {"you": 100, "me": 75, "foo": 116, "bar": 15};
keysSorted = Object.keys(list).sort(function(a,b){return list[a]-list[b]})
console.log(keysSorted);     // bar,me,you,foo

Solution 3:

Your objects can have any amount of properties and you can choose to sort by whatever object property you want, number or string, if you put the objects in an array. Consider this array:

var arrayOfObjects = [   
    {
        name: 'Diana',
        born: 1373925600000, // Mon, Jul 15 2013
        num: 4,
        sex: 'female'
    },
    {

        name: 'Beyonce',
        born: 1366832953000, // Wed, Apr 24 2013
        num: 2,
        sex: 'female'
    },
    {            
        name: 'Albert',
        born: 1370288700000, // Mon, Jun 3 2013
        num: 3,
        sex: 'male'
    },    
    {
        name: 'Doris',
        born: 1354412087000, // Sat, Dec 1 2012
        num: 1,
        sex: 'female'
    }
];

sort by date born, oldest first

// use slice() to copy the array and not just make a reference
var byDate = arrayOfObjects.slice(0);
byDate.sort(function(a,b) {
    return a.born - b.born;
});
console.log('by date:');
console.log(byDate);

sort by name

var byName = arrayOfObjects.slice(0);
byName.sort(function(a,b) {
    var x = a.name.toLowerCase();
    var y = b.name.toLowerCase();
    return x < y ? -1 : x > y ? 1 : 0;
});

console.log('by name:');
console.log(byName);

http://jsfiddle.net/xsM5s/16/

Solution 4:

For completeness sake, this function returns sorted array of object properties:

function sortObject(obj) {
    var arr = [];
    for (var prop in obj) {
        if (obj.hasOwnProperty(prop)) {
            arr.push({
                'key': prop,
                'value': obj[prop]
            });
        }
    }
    arr.sort(function(a, b) { return a.value - b.value; });
    //arr.sort(function(a, b) { a.value.toLowerCase().localeCompare(b.value.toLowerCase()); }); //use this to sort as strings
    return arr; // returns array
}

var list = {"you": 100, "me": 75, "foo": 116, "bar": 15};
var arr = sortObject(list);
console.log(arr); // [{key:"bar", value:15}, {key:"me", value:75}, {key:"you", value:100}, {key:"foo", value:116}]

Jsfiddle with the code above is here. This solution is based on this article.

Updated fiddle for sorting strings is here. You can remove both additional .toLowerCase() conversions from it for case sensitive string comparation.

Solution 5:

JavaScript objects are unordered by definition (see the ECMAScript Language
Specification
, section 8.6). The language specification doesn’t even guarantee that, if you iterate over the properties of an object twice in succession, they’ll come out in the same order the second time.

If you need things to be ordered, use an array and the Array.prototype.sort method.

Solution 6:

An “arrowed” version of @marcusR ‘s answer for reference

var myObj = {"you": 100, "me": 75, "foo": 116, "bar": 15};
keysSorted = Object.keys(myObj).sort((a,b) => myObj[a]-myObj[b])
alert(keysSorted);     // bar,me,you,foo

UPDATE: April 2017
– This returns a sorted myObj object defined above.

Object
 .keys(myObj)
 .sort((a, b) => myObj[a]-myObj[b])
 .reduce((_sortedObj, key) => ({
   ..._sortedObj, 
   [key]: myObj[key]
 }), {})

Try it here!

UPDATE: October 2018 – Object.entries version

Object
 .entries(myObj)
 .sort()
 .reduce((_sortedObj, [k,v]) => ({
   ..._sortedObj, 
   [k]: v
 }), {})

Try it here!