有没有一种方法可以用&&或||来表示逻辑

Question

Is there a way to represent logical not, with && or || or some statement like if or ?:

I want to implement this in some other way:

boolean isRunning = true;
startButton.setEnabled(!isRunning); // <<== ???

Answer 1

Assuming that you are doing this as an exercise, ternary operator lets you replace ! in a simple and straightforward way:

startButton.setEnabled(isRunning ? false : true);

As far as using && and || by themselves goes, this pair of operators is not functionally complete , ie there are operations that cannot be implemented by using a sequence of && s and || s alone; not ! operation is among operations that cannot be implemented with ands and ors.