Sorting Algorithm With A Json Object

[Fmdpa]

I'm trying to write an algorithm return an array sorted by a given property in a JSON object. Here's an example of what I want to sort:

obj_to_be_sorted = {'four' : {'num' : 4},'one' : {'num' : 1},'three' : {'num' : 3},'two' : {'num' : 2}} sort = function(obj, property, reverse_order) {	a = []		for (key in obj) {		a.push(key)	} 	return a.sort(a,  { /* I think it would involve the sort function... */ }} sorted_array = sort(obj_to_be_sorted, 'num', false); // should return the JSON keys sorted by the 'num' property, i.e. ['one', 'two', 'three', 'four']

I just don't know I would go about doing this. I'm thinking it would be only a few lines of code - very simple - but I'm just not good at writing algorithms yet. I would greatly appreciate any assistance you could give me.

[justsomeguy]

Since objects are unsorted, what exactly are you trying to return? Are you trying to return the keys from the object sorted by the num property, even though you're not returning that number?

[Fmdpa]

Yes.

[justsomeguy]

You'll probably need to build the array of keys like you're doing, and then you need to pass a compare function to the array.sort method, similar to PHP's usort. The compare function will need to use the two keys to look up the objects in the global object (the object you start with has to be global for this, or at least in the same scope as the compare function), and compare the properties that you want to compare to decide which should be sorted first. https://developer.mo...ects/Array/sort

[Fmdpa]

The real scenario is that I have an object (with a similar structure to the one I gave before) that I am building a search function for. The 'num' property would show the relevancy score for that item's key. Here's an example if I was searching for "foo"

obj_to_be_sorted = {'foo foo bar foo' : {'relevancy_score' : 3}, // score is 3 because "foo" was matched two times'foo bar' : {'relevancy_score' : 1}, // score is 1 because "foo" was matched once'bar bar' : {'relevancy_score' : 0}, // "foo" wasn't found in either of these so both of their scores are 0'bar' : {'relevancy_score' : 0}}

I want to then take the relevancy score and use it to sort the search results. EDIT: just saw your previous post; I'll see what I can come up with.

[Fmdpa]

This seems to do the trick!

sort_results = function(obj, field, reverse) {	a = []  	for(i in obj) {		a.push(i)	}      return a.sort(function(a, b ) {		var A = obj[a][field], B = obj[b][field];					 return (A < B ? (typeof A == 'number' && typeof B == 'number' ? A - B : -1) :				   (A > B ? 1 : 0)) * [-1,1][+!!reverse];	})}

[justsomeguy]

I believe the B parameter in the function needs to be lowercase. You're using "b" when accessing the property.

[Fmdpa]

Oops, I don't know how that happened. You are right. It must have happened somehow when I posted the code here. Fixed. Edit: I don't know what's going on, but the edit won't save the "B" as lowercase! Weird.

[Ingolme]

Oops, I don't know how that happened. You are right. It must have happened somehow when I posted the code here. Fixed. Edit: I don't know what's going on, but the edit won't save the "B" as lowercase! Weird.

Funny enough, I think I encountered that problem once on this forum. It's some kind of glitch.

[Fmdpa]

Did it occur before or after the forum update?

[Ingolme]

After, I think. But I can't imagine what kind of parseing they're doing to make that happen.

[Fmdpa]

I know, it's strange. I tried to find a place on IPS's website to file a bug, but I couldn't.

[justsomeguy]

I noticed that in Ingolme's response in PHP about using usort. It had a lowercase a and capital B. I bet it's related to emoticon parsing since the B comes before a close paren.

[Fmdpa]

Ah-ha, that sounds about right. I tried putting a space between the "b" and the parentheses and now it is display correctly.