Hi, I'm not really experieced in javascript but I don't understand the difference between 'new Array(1,2)' and '[1,2]'.
Could someone explain me what the difference is?

new Array(1,2) defines the array and it's size

array[1,2] is referencing an element in the array

I think he's talking about literal notation, Chris.

Literal arrays are still array objects, so I'm kinda surprised they don't compare equally...

same reason why

alert(Boolean([1, 2] == [1, 2]))

don't compare. they are both arrays but different objects.

whereas,

var arr = [1, 2];
var arr2 = arr;

alert(Boolean(arr == arr2)); <== returns true cause they reference the SAME object.

I think he's talking about literal notation, Chris.

maybe I should have read the thread title as part of the question instead of just the body text.

I see now.
One more dumb question:
Why did you use Boolean()?
Is alert(arr == arr2) different in some way?

yes, using the == comparison operator will return a Boolean value, I just used Boolean to define things a bit clearer and keep it nice and tite. no big reason.