CODEWITHSUNDEEP
javascriptjqueryhtmlarrays
Tallboy
Tallboy

Reputation: 13467

How do i check the length of this object?

I'm using a heavily modified version of jquery-tokeninput

it's essentially a text input box that allows multiple tags just like stack overflow.

You can get a return value with all the tags currently in the input by running this:

$("#no-custom-tokens").tokenInput("get")

The problem is, it returns the following for me:

enter image description here

if i try to call $("#no-custom-tokens").tokenInput("get").length it just says undefined.

I need to check if there are any u1, u2, etc inside this object (basically.. is the input blank).

I have considered doing...

if ($("#no-custom-tokens").tokenInput("get").u1.name != "")

Except that if you delete tokens, then add 2 more, it doesnt start at u1, u2... it starts at u3 and u4.

:/

Upvotes: 0

Views: 95

Answers (3)

nickf
nickf

Reputation: 546503

Check if it's empty:

function isEmpty(obj) {
    for (var i in obj) {
        if (obj.hasOwnProperty(i)) return false;
    }
    return true;
}

Check its length:

function objectLength(obj) {
    var size = 0;
    for (var i in obj) {
        if (obj.hasOwnProperty(i)) ++size;
    }
    return size;
}

// or:

function objectLength(obj) {
    return Object.keys(obj).length;
}

Upvotes: 1

Jeremy T
Jeremy T

Reputation: 1293

It looks like it's returning as an object, not an array, so there is no .length method. If you just want to check if anything's in the object, you can try to loop through the object and set a flag if it finds anything. So:

var isEmpty = true;
var tokens = $("#no-custom-tokens").tokenInput("get");
for (var i in tokens) {
    isEmpty = false;
    break;
}
if (isEmpty) {
    ...
}

Upvotes: 1

user1106925
user1106925

Reputation:

"I need to check if there are any u1, u2, etc inside this object (basically.. is the input blank)."

If you basically need to check for the existence of at least one property, and if the properties are enumerable, you can do this...

var has_props = false,
    obj = $("#no-custom-tokens").tokenInput("get");

for (var p in obj) {
    has_props = true;
    break;
}

console.log(has_props);

If you want to know how many, and again, if they're enumerable, you can use Object.keys...

var props_len = Object.keys($("#no-custom-tokens").tokenInput("get")).length;

You'll just need to shim it if you're supporting older browsers...

if (!Object.keys)
    Object.keys = function(o) {
        var keys = [];
        for (var k in o)
            if (o.hasOwnProperty(k))
                keys.push(k);

        return keys;
    };

Upvotes: 1

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