Question

I’m trying to construct a String in JS that can be passed into JSON as an with a very particular format. Desired result is a string of the following form:

[“PNG”,”350×150″,”127 KB”]

Where PNG correspond to a particular image’s type, where 350x150 is the image’s dimensions and where 127 KB is the image’s size. Each of these threee values are string variables:

var imgType = getImageType(); // Returns "PNG"
var imgDim = getImageDim(); // Returns "350x150"
var imgSize = getImageSize(); // Returns "127 KB"

var imgDescription = '["' + imgType + '","' + imgDim + '","' + imgSize + '"]';

// Sanity check
alert(imgDescription);

iVO.images[thisImage] = {
    "fizz":"buzz",
    "imgDesc":imgDescription,
    "foo":"bar"
}

alert(JSON.stringify(iVO));

The first alert (on the imgDescription variable) prints:

[“PNG”,”350×150″,”127 KB”]

So far, so good. However, the minute we pass it to the iVO construct and stringify the resultant JSON, it generates the following output (after I pretty print format it):

{
    "images":
    {
        "4490i45"":
        {
            "fizz":"buzz",
            "imgDesc":"[\"PNG\",\"350x150\",\"127 KB\"]",
            "foo":"bar"
        }
    }
}

All of my double quotes (“) have been escaped (\”)!!! Also, the value for imgDesc is enclosed in double-quotes, which is not what we want (see desired JSON below):

When I send this JSON back to the server its causing the server to choke.

Not sure what is going on here but I’ve tried several other suggestions, including replacing my double-quotes with '\x22' instances which didn’t help.

Any ideas as to what would fix this to get the desired result from JSON.stringify(iVO)? Ultimately that’s the only thing that matters, that the we end up sending the following to the server:

{
    "images":
    {
        "4490i45"":
        {
            "fizz":"buzz",
            "imgDesc":["PNG","350x150","127 KB"],
            "foo":"bar"
        }
    }
}

No escaped double-quotes, and the value for imgDesc is not double-quoted. Thanks in advance!

Answer 1

Why don’t you just put imgDescription as regular array

var imgDescription = [imgType , imgDim, imgSize];

Stringify should take care of what you are trying to do, otherwise you are passing imgDescription as a string and stringify would escape the quotes.

e.g.

var imgType = "PNG";
var imgDim = "350x150";
var imgSize = "127 KB";
var d = {
    "fizz":"buzz",
    "imgDesc":[imgType , imgDim, imgSize],
    "foo":"bar"
}
console.log(JSON.stringify(d));

Output:

{"fizz":"buzz","imgDesc":["PNG","350x150","127 KB"],"foo":"bar"}