That's per spec. Because the global object can be accessed as window (and several other things…), these global "variables" are therefore merely properties on th

That's per spec. Because the global object can be accessed as window (and several other things…), these global "variables" are therefore merely properties on the window object. It's worthwhile to point out that foo["bar"] and foo.bar are entirely equivalent in ES5 — just the former syntax allows more properties to be expressed as it allows an arbitrary string.