"This is complete rubbish. Common sense suggests that if it gave wildly different output then nobody would be using it. But yet everybody does. And likewise if

"This is complete rubbish. Common sense suggests that if it gave wildly different output then nobody would be using it. But yet everybody does. And likewise if each iPhone executed code differently people would be buying up old iPhones in droves to test. But again they don't." We use old iphones and older versions of ios to test on..... I don't really see how you could get by if you didn't.