An array inside of an array

Question

So here is the thing, I have a json file and inside of that I have an array, and inside of that I have another array.

This is how the json file looks.

{
    "keys": [
        {
            "game": "Counter-Strike: Global Offensive",
            "price": "5",
            "listofkeys": ["5555w-55w12-2d131","231a1-213x1-31313"]
        },
        {
            "game": "Crusader Kings II",
            "price": "20",
            "listofkeys": ["5555w-55w12-2d131","231a1-213x1-31313"]
        }
    ]
}

My questions is, is it possible to do it? Is it possible for me to use this, and then later do something like this:

(filename.json).keys.listofkeys.length

Is it possible to do .length like that here to check how many arrays there are in "list of keys" ?????? I have tried it for myself, and it does not seem to be working. I need confirmation on this though before I continue. If someone could be so kind to answer :)

Thanks!

because it is an array you still need to use indexing values. This can easily be checked in the browser itself. Create your page, include the json file, using the dev tools you can set breakpoints on the code or use the console to test your code. — user2417483
– user2417483, Commented Dec 25, 2016 at 1:40

Dekel · Accepted Answer · 2016-12-25 01:39:35Z

1

Not exactly.
In your example - the keys key is an Array, which mean it doesn't have a listofkeys attribute/key.

What you can do is check keys[0].listofkeys.length - This will take the first array in the keys key of your json-object and on that array - it will take the listofkeys key and check it's length.

answered Dec 25, 2016 at 1:39

Dekel

62.9k12 gold badges109 silver badges130 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Ahmad Othman Over a year ago

undefined:6 "listofkeys": ["5555w-55w12-2d131","231a1-213x1-31313"] ^

Dekel Over a year ago

You have a syntax error. You miss a comma after price": "5" in your json file. It should be price": "5",

Christos Lytras · Accepted Answer · 2016-12-25 01:49:08Z

Yes it is possible to load an external JSON file by using AJAX and then use the JSON.parse method to load that data to a javascript object variable:

data.json

{
    "keys": [
        {
            "game": "Counter-Strike: Global Offensive",
            "price": "5",
            "listofkeys": ["5555w-55w12-2d131","231a1-213x1-31313"]
        },
        {
            "game": "Crusader Kings II",
            "price": "20",
            "listofkeys": ["5555w-55w12-2d131","231a1-213x1-31313"]
        }
    ]
}

Javascript to load JSON file

function loadJSON(callback) {   

    var xobj = new XMLHttpRequest();
        xobj.overrideMimeType("application/json");
    xobj.open('GET', 'data.json', true);
    xobj.onreadystatechange = function () {
          if (xobj.readyState == 4 && xobj.status == "200") {
            // Required use of an anonymous callback as .open will NOT return a value but simply returns undefined in asynchronous mode
            callback(xobj.responseText);
          }
    };
    xobj.send(null);  
}

function check_json_data(json_data) {

    var obj = JSON.parse(json_data);

    console.log(obj);
    console.log("Keys length:", obj.keys.length);
    console.log("List of keys 1 length:", obj.keys[0].listofkeys.length);
    console.log("List of keys 2 length:", obj.keys[1].listofkeys.length);
}

loadJSON(check_json_data);

OUTPUT

See the console output of my example here: http://zikro.gr/dbg/html/json-load/

Collectives™ on Stack Overflow

An array inside of an array

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related