Consider this example Javascript code:

a = new Array();
a['a1']='foo';
a['a2']='bar';

b = new Array(2);
b['b1']='foo';
b['b2']='bar';

c=['c1','c2','c3'];

console.log(a);
console.log(b);
console.log(c);

Results in the Firebug console are as follows:

For a (the '[]' had to be expanded by clicking on the '+' button):

[]      
a1  "foo"   
a2  "bar"

For b:

[undefined, undefined]

For c:

["c1", "c2", "c3"]

My questions are:

  1. Am I using the array['key']='value' syntax correctly?
  2. Why isn't array b working as expected?
  3. Why are arrays a and c displayed differently in the console? It also seems that jQuery is unable to iterate through the array a with it's .each() method.
  4. Could you reccomend any good tutorials on Javascript array behaviour?

NOTE: Google Chrome's Firebug displays only [] for array 'a', without the option to expand it.

EDIT: Alright, it seems that arrays in Javascript have only numerical keys, so adding a string as a key name makes an object out of an array. But why doesn't jQuery's .each work with it?

$.each(a, function ()
    {
    alert ('derp');
    })

This code, appended to the script, produces no alerts.

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