string to array - javascript

Question

I am reading the plain text file in node.js using ajax call from client side.

Result : success gives the result as below.

 ""[{\"x\":233,\"y\":279,\"count\":1},{\"x\":256,\"y\":243,\"count\":6}]\n[{\"x\":233,\"y\":279,\"count\":1},{\"x\":256,\"y\":243,\"count\":6}]\n""

After parsing the above result :

   JSON.parse(result);

  "[{"x":233,"y":279,"count":1},{"x":256,"y":243,"count":6}] [{"x":233,"y":279,"count":1},{"x":256,"y":243,"count":6}] "

I want to change this string to array of objects,

Expected Result is array of objects:

   [{"x":233,"y":279,"count":1},{"x":256,"y":243,"count":6},
    {"x":233,"y":279,"count":1},{"x":256,"y":243,"count":6}
   ]

Ajax call Code

$.ajax({
        url: document.URL + "getData",
        method : "GET",
        success: function (result) {
            var info = JSON.parse(result);
            var object = JSON.parse(info);
            console.log(object);

        }
});

Any idea will be helpful.

can you just make the file node.json and just store the json, and use ajax to call it??? — Jeff Lee, Jun 07 '13 at 08:00
@JeffLee I am working only on retrieval part, No write permission — karthick, Jun 07 '13 at 08:01
Possible duplicate: http://stackoverflow.com/questions/5801699/in-node-js-how-do-i-turn-a-string-to-a-json — David Jashi, Jun 07 '13 at 08:02
http://jsfiddle.net/QBqZn/ comply error here. how can you parse it — Jeff Lee, Jun 07 '13 at 08:06
@JeffLee I think he has attempted to convert the output of a string constant into a variable declaration and left an extra pair of quotes around the string. — Alnitak, Jun 07 '13 at 08:11
wow, so you _already_ "double decoded" the output and yet you've _still_ got mangled JSON? — Alnitak, Jun 07 '13 at 08:28

Alnitak · Answer 1 · 2013-06-07T08:08:44.590

2

It looks to me like you've simply got double-encoded JSON. Just run it through JSON.parse() a second time.

EDIT actually, that's not quite right - the output contains two JS arrays, with a \n separator and no enclosing array. You will have to manipulate the data a bit (looking at that now) to make it parseable a second time.

EDIT2 This appears to work, albeit that your current var res line includes an extra pair of surrounding quotes that aren't legal so in this test I've removed them:

var res =  "[{\"x\":233,\"y\":279,\"count\":1},{\"x\":256,\"y\":243,\"count\":6}]\n[{\"x\":233,\"y\":279,\"count\":1},{\"x\":256,\"y\":243,\"count\":6}]\n"

var out = JSON.parse(res.replace(/]\s*\[/g, ','));

edited Jun 07 '13 at 08:08

answered Jun 07 '13 at 08:02

Alnitak

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SyntaxError: JSON.parse: unexpected non-whitespace character after JSON data while second time parsing – karthick Jun 07 '13 at 08:05
@Swift you're wrong - I did realise it, but the OP wanted the objects from the two arrays to be merged into a _single_ array. – Alnitak Jun 07 '13 at 08:23

Michael Geary · Accepted Answer · 2013-06-07T08:18:42.803

2

That is some seriously messed-up JSON. There's an extra quote mark at each end, and ]\n[ in the middle where there should be a ,.

You really should fix your server to generate valid JSON, but if you can't, you could tweak it like this:

var res = '"[{\"x\":233,\"y\":279,\"count\":1},{\"x\":256,\"y\":243,\"count\":6}]\n[{\"x\":233,\"y\":279,\"count\":1},{\"x\":256,\"y\":243,\"count\":6}]\n"';

var resfix = res.replace( /^"|"$/g, '' ).replace( ']\n[', ',' );

JSON.parse( resfix );

I changed the extra set of quotes at the very outside of your var res = string to make it a valid JavaScript string for testing.

edited Jun 07 '13 at 08:18

answered Jun 07 '13 at 08:08

Michael Geary

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that first `var res` line copied from the OP isn't legal. If the enclosing double quotes aren't really there then the first `.replace()` is unnecessary. – Alnitak Jun 07 '13 at 08:12
@karthick.k I don't see how that can work when the `var res` you've supplied isn't even legal JS. – Alnitak Jun 07 '13 at 08:14
@Alnitak - good catch, thanks. I'd changed the outermost `"` to `'` in my test case but forgot to copy it over to the answer that way. – Michael Geary Jun 07 '13 at 08:14
@MichaelGeary it's unclear whether the outer double quotes the OP put in the question ever even existed. – Alnitak Jun 07 '13 at 08:15
@Alnitak - True, but the code I posted would work the same with or without them. – Michael Geary Jun 07 '13 at 08:16

string to array - javascript

2 Answers2