Convert a javascript string into a 2-dimensional array

Question

I have this data coming from a REST method using jquery's getJSON method.

"[Date.UTC(2010,0,0,0,0,0,0), 157],[Date.UTC(2010,0,0,0,0,420,1), 157],[Date.UTC(2010,0,0,0,0,420,2), 282],[Date.UTC(2010,0,0,0,0,600,3), 282],[Date.UTC(2010,0,0,0,0,600,4), 125],[Date.UTC(2010,0,0,0,0,900,5), 125],[Date.UTC(2010,0,0,0,0,900,6), 282],[Date.UTC(2010,0,0,0,0,2100,7), 282],[Date.UTC(2010,0,0,0,0,2100,8), 125],[Date.UTC(2010,0,0,0,0,2400,9), 125],[Date.UTC(2010,0,0,0,0,2400,10), 295],[Date.UTC(2010,0,0,0,0,3600,11), 295],[Date.UTC(2010,0,0,0,0,3600,12), 125],[Date.UTC(2010,0,0,0,0,3900,13), 125],[Date.UTC(2010,0,0,0,0,3900,14), 288],[Date.UTC(2010,0,0,0,0,5100,15), 288],[Date.UTC(2010,0,0,0,0,5100,16), 125],[Date.UTC(2010,0,0,0,0,5400,17), 125]"

It comes back as a string. I need to parse it into a two dimensional array. Each item in the array should have a date and a value.

I also have full control over the REST method, so I could change the way the data returns. I'm interested in making this as fast as possible.

Here's what we are doing now which I think could be improved:

 var jqxhr = $.getJSON(getDataURL, function(dataResult) {
        var result = dataResult;

        result =result.replace(/\]\,\[/g, ']:[');
        result = result.replace(/\)\,/g, ');');

        var tempArray = result.split(':');

        var myarray = new Array();
        myarray[0] = new Array(2); // Make the first element an array of two elements
        for(i = 0; i < tempArray.length; i ++)
        {
          myarray[i] = tempArray[i].split(';');
          myarray[i][1] = myarray[i][1].replace(/\"/g,'');
          myarray[i][1] = myarray[i][1].replace(/\]/g,'');  
          myarray[i][0] = myarray[i][0].replace(/\[/g,'');                             
        }                                                               
    })

as horrible as it sounds, I'd put brackets at the start and end of the string and use eval — Joseph Marikle, Aug 22 '11 at 21:49
@Joseph I thought about using jQuery.parseJSON but I don't think my string is valid for that function. http://api.jquery.com/jQuery.parseJSON/ I'll try sending back the data so it's valid. — Nate, Aug 22 '11 at 21:54

score 3 · Accepted Answer · answered Aug 22 '11 at 21:52

3

As much as I'm going to get flack for this (eval tends to be a security risk), I would just do

var myarray = eval("[" + result + "]");

answered Aug 22 '11 at 21:52

Joseph Marikle

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I was going to post the same answer. In this case, `eval` works (you don't even need to add the enclosing brackets). But one should know what he is doing before using `eval`. Could start by reading this SO thread: http://stackoverflow.com/questions/197769/when-is-javascripts-eval-not-evil – bfavaretto Aug 22 '11 at 21:56
@bfavaretto Wow! thanks for the link! I will be sure to read it when I get home. Also, I tried it without the brackets and it only assigned it the last array in the string so I think the brackets are necessary. Again, thank you for the link! – Joseph Marikle Aug 22 '11 at 22:01
You're right about the brackets, sorry! I tested with only part of the original string... – bfavaretto Aug 22 '11 at 22:05
*eval* is not, of itself, a secuirity risk. Running code from unknown sources without checking might be, but you don't need *eval* for that. – RobG Aug 22 '11 at 23:34

score 0 · Answer 2 · answered Aug 22 '11 at 21:51

0

You should use JSON to return data from your server to your JS script. That will be pretty easier to manipulate it as an array.

answered Aug 22 '11 at 21:51

ldiqual

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Convert a javascript string into a 2-dimensional array

2 Answers2