3 
{
  "TR":{
    "total_fans":1848,
    "country_name":"Turkey"
  },
  "US":{
    "total_fans":1097,
    "country_name":"United States"
  },
  "DE":{
    "total_fans":915,
    "country_name":"Germany"
  },
  "MX":{
    "total_fans":1148,
    "country_name":"Mexico"
  },
  "RS":{
    "total_fans":359,
    "country_name":"Serbia"
  },
  "IT":{
    "total_fans":798,
    "country_name":"Italy"
  }
}

I would like to sort this based on fans. For instance, in this case it should be "TR", "MX", "US"... and so on using JS and Underscore if that helps. Thanks!

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2
  • Syntax error on your object... is that the whole object? Commented Dec 12, 2013 at 23:43
  • i edited it and i guess i messed something up, but it looks like Doorknob fixed it. Is there a way to format it in stackoverflow without just spacing? Commented Dec 12, 2013 at 23:46

5 Answers 5

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4

JavaScript objects are unordered, so you won't be able to sort or otherwise define a specific order.

You could convert the properties to an Array, and sort that instead, but that's about as close as you'll get.

Since it seems you want to sort by number of fans, you can do this.

Object.keys(myObject)
    .sort(function(a,b) {
        return myObject[a].total_fans - myObject[b].total_fans;
    }).forEach(function(key) {
        console.log(myObject[key]);
    });

To support IE8 and lower, you'll need patches for Object.keys and Array.prototype.forEach.

And as Bruce Lim noted, this is an ascending sort. To descend, swap the operands of the - operator after the return.

return myObject[b].total_fans - myObject[a].total_fans;
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5 Comments

he actually wants to sort by fans.
@natecraft1 changed the property to total_fans btw. It works to sort ASC. To sort DSC: return myObject[b].total_fans - myObject[a].total_fans;
+1 Whoah, nice work cookie monster! I forgot all about Object.keys...which does exactly what I was trying to do myself with Object.ownProps, but is more standard. Yours is clearly the best answer.
yo cookie, good stuff. What would you name this question so that the most people who have the same issue run into it? I am still learning the lingo ;)
@natecraft1: I think your title is very descriptive of what you were asking for. Maybe key:value pairs instead of key:object, but otherwise you've got the lingo nailed. And you probably noticed that I didn't use the forEach from underscore, but it would be the same, only passing the sorted array as the first argument. :)
1

No underscore is necessary if you don't care about IE < 9. Given your structure being in a variable obj:

var sorted = Object
   .keys(obj)
   .map(function(key) {
       // Put the country in the item?
       obj[key].country = key;
       return obj[key];
   })
   .sort(function(a, b) {
       if (a.total_fans > b.total_fans) {
           return -1;
       } else if (b.total_fans > a.total_fans) {
           return 1;
       }
       return 0;
   });

This will give you an Array sorted with the items having the most fans being first, and the country code added to each item in case you need that (omit if unnecessary).

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1 Comment

jacob thanks this is an awesome answer and i learned a lot from it
1

Try sorting with an array:

var array = [];

// copy object to array
for (var x in yourObject) array.push([x, yourObject[x].total_fans]);

// sort array
array.sort(function(item1, item2) { return item1[1] - item2[1] });

// now get the keys
var keys = [];
for (var i = 0; i < array.length; i ++) keys.push(array[i][0]);

// keys = ["RS", "IT", "DE", "US", "MX", "TR"]

Note that the key-getting step could be easier with map if you don't care about old IEs.

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Comments

1

UPDATE: Thanks to a heated but useful exchange with Doorknob, I realized that he had an excellent point about being careful about modifying Object.prototype. I modified the answer to make the extension of Object.prototype less intrusive by making the new method non-enumerable. Thanks, Doorknob!

UPDATE 2: I realize now that the OP's wisely selected correct answer has the right of it. Object.keys does exactly what my ownProps method (see below) does, and it's a standard (though you still have to polyfill in IE8). I would just delete this answer since cookie monster nailed it, but I think this is a useful discussion and even though ownProps is redundant with Object.keys, it might teach someone...something.

I wrote a convenience function called ownProps which returns all the property names of an object (excluding properties in the prototype chain). It's a more functional way of doing what Doorknob is suggesting above:

// retrieves all of the properties of an object as an array, 
// omitting properties in the prototype chain; note that we use
// Object.defineProperty so we can make this non-enumerable, thereby
// making a safer modification of Object.prototype
Object.defineProperty(Object.prototype,'ownProps',{
  enumerable: false,
  value: function() {
    var props = []; for( var prop in this ) { 
        if( this.hasOwnProperty( prop ) ) props.push( prop ); 
    } 
    return props;
  }
});

Armed with this, you can sort your object using a custom sort function:

var obj = {"TR":{"fans":1848,"country_name":"Turkey"}/*...*/}

var sortedKeys = obj.ownProps().sort(function(a,b){
    return obj[a].fans - obj[b].fans;
});
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12 Comments

Disagree, Doorknob. One of the beauties of JavaScript. Not everything Douglas Crockford says is plated in gold.
Well, let's say someone goes and does if (someVariable.ownProps === undefined) someVariable.ownProps = ['some', 'stuff']. Oops, your code just broke that :(
As opposed to...anything else you do? What if I made a custom function NOT on Object.prototype that does that? Someone could come along and overwrite that.
In JavaScript, there are a million opportunities to screw things up...it's part of the nature of the beast. While I don't go willy-nilly modifying Object.prototype for the fine reasons you're laying down, some well-placed and sensible extensions are not the end of the world.
FWIW, "Not everything Douglas Crockford says is plated in gold." is a statement I can entirely agree with! ;-D
|
-1

Solution: http://jsfiddle.net/az7XN/

lets say that whole your object of fans is a fansObj:

for(prop in fansObj){
   console.log(prop, fansObj[prop]);
}

output example: TR, {"fans":1848,"country_name":"Turkey" }

before for circle declare array variable and push there each obj:

var arr = [];
for(prop in fansObj){
   console.log(prop, fansObj[prop]);
   arr.push(fansObj[prop]);
}

then sort:

arr.sort(function(a,b){parseInt(b['total_fans'],10) - parseInt(a['total_fans'])});

parseInt(obj,10) will accept convert object as decimal to integer.

Now you have sorted array (depending on comparison inside sort function (a-b=desc or b-a=asc)).

Used function:

for..in

Array.prototype.sort()

parseInt()

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3 Comments

UPDATE: added sort. Fistly I wrote how you can go throw all properties in object, then added sort.
There's no need for the parseInt...the total_fans property is already a number.
@EthanBrown yeah, you are right, but I thinked that was string inside JSON, so I added parse. It even better to have integer parser, cause in javascript you can set anything to total_fans

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