The final keyword for Java

As with static, it is added to achieve some special requirements, and differs from the modifier keywords of ordinary variables.

1.final is the final meaning, so there is no way to modify the meaning inside

So

1.1. A class that is final modified cannot be inherited (childlessness)

1.2. The final modified method cannot be rewritten (and cannot be changed).

1.3. A final modified variable can only be assigned one time, and to be assigned at the time of declaration or the assignment displayed in the construction method (this is also called invariant constant) 1.4.final cannot be used to modify abstract classes, abstract methods, construction methods (this is a supplement to 1.2)

( because abstract classes are used to be inherited, abstract methods are used to be rewritten by others, and construction methods can be rewritten )

The final keyword for Java