Javascript: Replace backslashes with double backslashes

Question

I'm currently having the problem mentioned in the title and I'm somehow not finding a way to properly replace backsashes with double backslashes, so that I can properly give the string to a webservice as parameters. Let me show you what I tried. Some of these do actually work for some other people, but not for me... I'm currently testing this with FF18.0.1

WSParameters.replace(/\\/g, "\\\\\\\\");
WSParameters.replace("\\", "\\\\\\\\");
WSParameters.replace(/\\/g, "\\\\");
WSParameters.replace(/\\/g, "\\");
WSParameters.replace(/\\/g, "\");
WSParameters.replace("\\", "\\\\");

Thanks a lot in advance

EDIT: I should mention that it's somehow parsed into JSON and with firebug I see the backslash in the source string, but not in the JSON view. Maybe there is another way? But somehow it's already failing at the replacement of the backslashes.

EDIT2:

if (noAction == false) {
    $.ajax({
        type: "POST",
        url: "WebService.asmx/" + webMethod,
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        async: pAsync,
        data: WSParameters,
        success: function callFunction(result) { processPOSTResults(result, pType, pNot);},
        error: function (xhr, ajaxOptions, thrownError) {
            alert('Error while communicating with WebAdmin web service. - ' + xhr.status + " " + thrownError);
        }
    });
}

Solution

WSParameters.replace(/\\/g, "\\\\"); should do it, and in FF18 as well. Notice that if you use JSON.stringify, this is done automatically. Also watch out that many console outputs (Firebug etc) do surround string contents with quotes, but do not escape them.

Comments

[ArgisIsland]

Thanks Bergi, I don't use JSON stringify, please se my EDIT 2 for the JSON WS part.

[Bergi]

However maybe you should use it for posting JSON? What is WSParameters, how do you get it?

[ArgisIsland]

The WSParameters variable is a string and looks like this: {param1: 'abc', param2: 'def', list1: ['4711','4712']}

[ArgisIsland]

I'll have a look at this, thanks. But is this also possible with dynamically generated lists and nested lists?

[Bergi]

How did you get that string? It's not valid JSON at all.

[ArgisIsland]

I built it based on the experience I made, this was the only format tht worked for me.

[Bergi]

Your webservice only accepts javascript object literals, no JSON???

[ArgisIsland]

I guess it also accepts JSON, but I couldn't figure out the correct use and then went with the more convenient format. However it seems that this was the wrong decision.

[Bergi]

Yes. Use an object, and JSON.stringify (like here).

[ArgisIsland]

Just wanted to let you know that using the JSON format and JSON.stringify solved the problem with the backslash in the web service parameters. Thanks again!