Shall we add && operator as many as we can?
yes, there is no limit! But if there is at least one element that is always false, all the expression will be evaluate at false. In the same way, if there is one element that is always true, it will have no effect on the expression and can.be removed...
There is no limitation of using && operator, it's upto user choice but make sure you place it logically else you make either get a wrong answer or maybe an error.