I am kind of new to the world of interface, and i found JSON is amazing, so simple and easy to use. But using JS to handle it is pain !, there is no simple and direct way to push a value, check if it exists, search, .... nothing !

and i cannot simply add a one single value to the json array, i have this :

loadedRecords = {}

i want to do this :

loadedRecords.push('654654')
loadedRecords.push('11')
loadedRecords.push('3333')

Why this is so hard ???!!!

I am kind of new to the world of interface, and i found JSON is amazing, so simple and easy to use. But using JS to handle it is pain !, there is no simple and direct way to push a value, check if it exists, search, .... nothing !

and i cannot simply add a one single value to the json array, i have this :

loadedRecords = {}

i want to do this :

loadedRecords.push('654654')
loadedRecords.push('11')
loadedRecords.push('3333')

Why this is so hard ???!!!

• javascript
• json

• I think you're looking for setters. see my answer below. – batman Commented Jun 30, 2011 at 16:51

7 Answers 7

Because that's an object, not an array.

You want this:

var = loadedRecords = []
loadedRecords.push('1234');

Now to your points about JSON in JS:

there is no simple and direct way to push a value

JSON is a data exchange format, if you are changing the data, then you will be dealing with native JS objects and arrays. And native JS objects have all kinds of ways to push values and manipulate themeselves.

check if it exists

This is easy. if (data.someKey) { doStuff() } will check for existence of a key.

search

Again JSON decodes to arrays and objects, so you can walk the tree and find things like you could with any data structure.

nothing

Everything. JSON just translates into native data structures for whatever language you are using. At the end of the day you have objects (or hashes/disctionaries), and arrays which hold numbers strings and booleans. This simplicity is why JSON is awesome. The "features" you seek are not part of JSON. They are part of the language you are using to parse JSON.

Well .push is an array function.

You can add an array to ur object if you want:

loadedRecords = { recs: [] };

loadedRecords.recs.push('654654');
loadedRecords.recs.push('11');
loadedRecords.recs.push('3333');

Which will result in:

loadedRecords = { recs: ['654654', '11', '3333'] };

{} is not an array is an object literal, use loadedRecords = []; instead.

If you want to push to an array, you need to create an array, not an object. Try:

loadedRecords = [] //note... square brackets
loadedRecords.push('654654')
loadedRecords.push('11')
loadedRecords.push('3333')

You can only push things on to an array, not a JSON object. Arrays are enclosed in square brackets:

var test = ['i','am','an','array'];

What you want to do is add new items to the object using setters:

var test = { };
test.sample = 'asdf';
test.value = 1245;

Now if you use a tool like FireBug to inspect this object, you can see it looks like:

test {
    sample = 'asdf,
    value = 1245
}

Simple way to push variable in JS for JSON format

var city="Mangalore";
var username="somename"

var dataVar = {"user": 0,
                "location": {
                    "state": "Karnataka",
                    "country": "India",  
                },
            }

            if (city) {
                dataVar['location']['city'] = city;
            }
            if (username) {
                dataVar['username'] = username;
            }

Whats wrong with:

var loadedRecords = [ '654654', '11', '333' ];