Get URL array variables in javascript/jquery

Question

I've got a bunch of parameters being passed to a page by URL variables. The URL looks sort of like:

file.aspx?category[]=1&category[]=7&category[]=3&id=8az

Using the jQuery getUrlParam extension I can get url variables very easily, but rather than returning category as an array (which is what I want) it gets returned as null.

Is there a way for me to read these into a javascript array?

score 3 · Answer 1 · edited May 23 '17 at 12:01

I previously pointed to this question: Get QueryString values with jQuery - but as @Crescent Fresh pointed out, those examples don't deal with arrays in the query string (and besides, they're a bit slow I think.

So I cooked up my version of this function:

function getQueryString () {
    var ret = {};
    var parts = (document.location.toString().split('?')[1]).split('&');
    for (var i = 0; i < parts.length; i++) {

        var p = parts[i].split('=');
        // so strings will be correctly parsed:
        p[1] = decodeURIComponent(p[1].replace(/\+/g, " "));

        if (p[0].search(/\[\]/) >= 0) { // then it's an array
            p[0] = p[0].replace('[]','');

            if (typeof ret[p[0]] != 'object') ret[p[0]] = [];
            ret[p[0]].push(p[1]);
        } else {
            ret[p[0]] = p[1];
        }
    }
    return ret;
}

But there are caveats. It will only work on a correctly formed query string - there's no error detection. Also, it does not work on numbered/indexed arrays.. that is when your array is defined in the query string as:

?category[3]=1&category[4]=7&category[20]=3&id=8az

It would be trivial to add to the .search() query a regex for finding that as well, but I'm not the best regex expert... anybody got ideas?

Not a single answer there will do what the OP is asking for (i.e., array detection in the query string). — Crescent Fresh, Feb 11 '11 at 04:27
You're right. I didn't realize - I just saw a complicated function and I thought something that complicated must do it right.. but it didn't. I added my version. — arnorhs, Feb 11 '11 at 09:20
If I could pick two answers I would. This answers what I really asked, Timothy's answers what I really needed. — Hibiscus, Feb 15 '11 at 18:38

score 1 · Accepted Answer · answered Feb 11 '11 at 02:57

1

Shouldn't it be: file.aspx?category=1&category=7&category=3

answered Feb 11 '11 at 02:57

Timothy Khouri

31,315
21
88
128

Acutally yes, with getUrlParam that does return an array as I needed. – Hibiscus Feb 12 '11 at 22:47
Because, as he just said... "actually yes, [my suggestion] does" do what he needed. – Timothy Khouri Feb 14 '11 at 05:22
but then the query string is incompatible with the server software...? – arnorhs Feb 17 '11 at 01:02
@arnorhs - No, it was most likely that he didn't mean to add the "[]" when he was building his query string. – Timothy Khouri Feb 18 '11 at 02:54

Get URL array variables in javascript/jquery

2 Answers2