Question

I am trying to set up an array in jQuery and I then need to do a for loop on it. But it seems that I cant use an associative array for some reason?

var items = new Array();
items['foo'] = 123456;
items['bar'] = 789012;
items['baz'] = 345678;
items['bat'] = 901234;
alert(items.length);

This is just a test, but it return 0?

Answer 1

You can’t make associative array in JavaScript like what you want, instead you can use Object.

For example:

var items = {
  foo : 123456,
  bar : 789012,
  baz : 345678,
  bat : 901234
}

And to calculate the length you can do:

var getObjectSize = function(obj) {
    var len = 0, key;
    for (key in obj) {
        if (obj.hasOwnProperty(key)) len++;
    }
    return len;
};

Use: getObjectSize(items); // output: 4

For more see here.

Another one is:

Object.keys(items).length;

But not supported by all browsers.