Array via POST (Ajax)

Question

Okay, this seems to be the most straight forward thing, but I really have no idea why it's doing this nor find anyone else with this problem.

Here's my issue, I'm sending a POST request like so;

  $.ajax({
      type: "POST",
      url: '/user/sell',
      data: data,
      success: function(data) {
        console.log('Call was successful');
      }
    });

In the data object is an array called items . When I log the data object it's fine, like it should be, however when I log the data object in my express function the items array changes to items[] for no reason..

NodeJS

'items[]': '15716345'

JS (Browser)

items: [15716345]

Any idea what's happening here?

Below is the entire version of the code. Entire block (frontend) // Validate address if($('.block.payment .wrapper input:eq(0)').val() !== $('.block.payment .wrapper input:eq(1)').val()){ return error('Fields do not match'); }

// Get known data
var type = $('.body.inventory .methods .method.selected').data('type'),
    items = [];

var data = {
  type,
  address: $('.block.payment .wrapper input:eq(0)').val()
}

if(type === 'steam'){
  var app = $('.body.inventory .sub-methods .method.selected').data('app');
  data['app'] = app;

  $('.body.inventory .item[data-app="'+app+'"].selected').each(function(){
    items.push($(this).data('id'));
  });
}else{
  $('.body.inventory .item[data-type="'+type+'"].selected').each(function(){
    items.push($(this).data('id'));
  });
}

data['items'] = items;

// Execute route or smt
$.ajax({
  type: "POST",
  url: '/user/sell',
  data: data,
  success: function(data) {
    console.log('Call was successful');
  }
});

Backend

router.post('/sell', function(req, res, next) {
  try {
    console.log(req.body);
    res.send({
      success: 1
    });
  } catch(e) {
    if(e) console.log(e);

    res.send({
      success: 0,
      error: e
    });
  }
});

Answer 1

Set JSON body parser middleware for requests to your expressJS application.

const bodyParser = require('body-parser');

app.use(bodyParser.json())

And in the AJAX request, make the contentType to be application/json and not the default of application/x-www-form-urlencoded; charset=UTF-8' application/x-www-form-urlencoded; charset=UTF-8' .

$.ajax({
  contentType: 'application/json',
  type: "POST",
  url: '/user/sell',
  data: data,
  success: function(data) {
    console.log('Call was successful');
  }
});

Answer 2

Assume that is your Array List, which you want to POST.

object[] Obj = new object[1];
Obj [0] = "value1"
Obj [1] = "Value2"
Obj [3] = {"CollectionValue1, CollectionValue2"}

$.ajax({
  url: '../Controller/MethodName',
  type: 'post',
  datatype: 'json',
  async: false,
  contentType: "application/json; charset=utf-8",
  data: JSON.stringify({ ControllerParameterName: Obj }), <!-- Obj is your Array -->
  success: function (data) {
    alert(data.Response);
  }
});