creating nested array javascript

Question

Have looked at many examples but cant seem to get to make an nested array to store some data nicely. How can I get the following code to work? It gives me an error now:

var shipdata = [];

shipdata['header']['bedrijfsnaam'] = $('[name="bedrijfsnaam"]').val();
shipdata['header']['naam'] = $('[name="naam"]').val();
shipdata['header']['straat'] = $('[name="straat"]').val();
shipdata['header']['postcode'] = $('[name="postcode"]').val();
shipdata['header']['plaats'] = $('[name="plaats"]').val();
shipdata['header']['telefoon'] = $('[name="telefoon"]').val();
shipdata['header']['email'] = $('[name="email"]').val();
shipdata['header']['instructies'] = $('[name="instructies"]').val();
shipdata['header']['ordernummertje'] = $('[name="ordernummertje"]').val();

$(".pakketten").each(function(index, element) {

            index++;
            shipdata['pakketten']['pakket'+index]['lengte'] = $('[name="lengte'+index+'"]').val(),
            shipdata['pakketten']['pakket'+index]['breedte'] = $('[name="breedte'+index+'"]').val(),
            shipdata['pakketten']['pakket'+index]['hoogte'] = $('[name="hoogte'+index+'"]').val(),
            shipdata['pakketten']['pakket'+index]['gewicht'] $('[name="gewicht'+index+'"]').val()


        });

Probably im doing this all wrong, but some pointers would be welcome.

Thanks!

Seems like you actually want an object, arrays are referenced via index, objects have actual key/val pairs. — tymeJV
– tymeJV, Commented Jan 28, 2014 at 14:37
It's an object, not an array. Javascript doesn't have arrays with string keys. — gpgekko
– gpgekko, Commented Jan 28, 2014 at 14:37
You should first initialize 1st level arrays, like shipdata['header'] = [] — Kiril
– Kiril, Commented Jan 28, 2014 at 14:40

Sirko · Accepted Answer · 2014-01-28 14:42:14Z

4

First of all, you are creating an object and not an array, so use {} instead of [] for the main container.

Second, when inserting multiple values at the same time, you can use a much more compact notation:

var shipdata = {
  'header': {
    'bedrijfsnaam': $('[name="bedrijfsnaam"]').val(),
    'naam': $('[name="naam"]').val()
    '...': '...'
  },
  'pakketten': []
};

$(".pakketten").each(function(index, element) {
            shipdata['pakketten'].push({
              'lengte': $('[name="lengte'+index+'"]').val(),
              'breedte': $('[name="breedte'+index+'"]').val(),
              '...': '...'
            });
});

Besides, anytime you want to access an object or array in any way, you have to initialize it beforehand as already mentioned by @antyrat.

answered Jan 28, 2014 at 14:42

Sirko

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2 Comments

Snuur Over a year ago

thanks this seems to work, but can I create a JSON object out of this? Because now the top part is an object, and the pakketten part is an array.

Sirko Over a year ago

@Snuur If you want to create a JSON-string out of it, it does not matter, whether the content is an array or an object. In both cases you can use JSON.stringify( shipdata ) to get the JSON string.

antyrat · Accepted Answer · 2014-01-28 14:44:55Z

2

You need to create objects each time you want to have nested array:

var shipdata = {};
shipdata['header'] = {};
shipdata['header']['bedrijfsnaam'] = $('[name="bedrijfsnaam"]').val();
//...

shipdata['pakketten'] = {};

$(".pakketten").each(function(index, element) {

    index++;
    shipdata['pakketten']['pakket'+index] = {};
    shipdata['pakketten']['pakket'+index]['lengte'] = $('[name="lengte'+index+'"]').val(),
    // ...

Answer updated due to comments as arrays didn't have string indexes.

edited Jan 28, 2014 at 14:44

answered Jan 28, 2014 at 14:37

antyrat

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