Parse Array of JSON objects in NodeJS

Question

I am wondering how can I parse Array of JSON objects in NodeJS?

I want to post JSON array to the server, and be able to use the received array as a regualar JavaScri

Answer 1

I'll try to explain this. First of all, you are crating a json string on the client.

JSON.stringify(QuestionsArray)

Then on the server, you are doing the same again:

JSON.stringify(req.toString()) // this is not needed

Then you parse the double stringifyed json string to a javascript object:

JSON.parse(JSON.stringify(req.toString()))

So now you actually have to parse it twice :). If you just stringify it on the server as you are now, and just call:

var arr = JSON.parse(req.toString());

You will get a javascript object that you can access like this:

res.end(arr[0].QuestionText.toString());

Have a look at this jsFiddle and open your developer tools. Look at the console when it runs and you will see where the problem is: example

Answer 2

You may actually send the JSON directly to server.

    $.ajax({
        url: "/echo",
        type: 'POST',
        data: JSON.stringify(QuestionsArray),
        processData: false,
        contentType: 'application/json'
    }).success(function (data) {
        alert(data);
    });

And in node.js, use bodyParser.json to get it back.

app.use(bodyParser.json({}));

app.post('/echo', function (req, res) {
    var array = req.body;
    res.end(array[0]["QuestionText"].toString());
});

By the way, do not use Array as variable name because Array represent the Array class used by JavaScript and your code has overwritten it.

Answer 3

In your app.js:

var bodyParser = require("body-parser");
...
app.use(bodyParser.urlencoded({extended: true}));

Then you can just use req.body to get the posted values:

app.post('/echo', function (req, res) {
    var Array = req.body.data;
    res.end(Array[0]["QuestionText"].toString());
});

In front-end, don't do any stringifying:

$.post("/echo", {data: QuestionsArray}, function (data) {
    alert(data);
});