Nie rozumiem zachowania usuwania vars w JavaScript
Oto problem:
var x = 5;
window.x === x // true. x, as it seems, is a property of window
delete x; // false
delete window.x; // false;
ALE
window.x = 5;
delete window.x; // true
I
window.x = 5;
delete x; // true
Jakie jest wyjaśnienie takiego zachowania?