Question

I have code that makes an AJAX call to an MVC controller method and it’ll work without a hitch if I do this:

var obj = '{"titlename":"whatever"}';
            $.ajax({
                type: "POST",
                url: "/Titles/Yo",
                contentType: "application/json; charset=utf-8",
                dataType: 'json',
                data: obj,
                success: function (result) {
                    $("#title_field").html(result.TitleName);
                }
            });

But if I do this:

var stringed="whatever"
            var obj = '{"titlename":stringed}';
            $.ajax({
                type: "POST",
                url: "/Titles/Yo",
                contentType: "application/json; charset=utf-8",
                dataType: 'json',
                data: obj,
                success: function (result) {
                    $("#title_field").html(result.TitleName);
                }
            });

It craps out on me with an “invalid JSON primitive” error. I keep trying various single and double quote permutations, but they all keep giving me the same error. How can I insert a string variable into a JSON object?

Answer 1

Try this:

var stringed = "whatever";
var obj = '{"titlename": "' + stringed + '"}';

Also you may want to take a look at a JSON2 library, which can stringify your data automatically.