Javascript count keys in braces of function

Question

I call a function like so:

update_insert('information',{
    element_id: 1,
    type: 'menu',
    info: 'Hi how are ya?',
    new_window: ''
});

The function is:

function update_insert(table,data){
    alert(data.length);
}

I am trying to get the number of keys that I inserted into the function, and eventually get the names of the keys, dynamically with a loop. How can I achieve this?

Answer 1

Objects don't have the .length attribute like arrays do in JavaScript. You'll need to use a function to count the number of items in an object:

getObjectLength = function(obj) {

    var size = 0, key;

    for (key in obj) {
        if (obj.hasOwnProperty(key))
            size++;
    }

    return size;
}

EDIT:

And to get the keys from an object:

getObjectKeys = function(obj) {

    var keys = [];

    for (var key in obj) {
        keys.push(key);
    }

    return keys;
}