Java Learning (vi) Object-oriented final keyword

1. Methods that are modified by fnial cannot be rewritten, and are commonly used for cosmetic classes, methods, variables

/*final can modify the class, method, variable characteristics: Final can be decorated class, the class cannot be inherited. Final can modify the method, and the method cannot be overridden. (Overwrite, duplicate) Final can modify the variable, and the variable cannot be re-assigned.            Because this variable is actually constant. Constant: A: literal constant "Hello", 10,true B: custom constant Final int x = ten;*///Final class Fu//unable to inherit from final FuclassFu { Public intnum = 10;  Public Final intnum2 = 20; /*Public final void Show () {}*/}classZiextendsFu {//Show ( ) in Zi cannot overwrite show () in Fu     Public voidShow () {num= 100;                SYSTEM.OUT.PRINTLN (num); //cannot assign a value to the final variable num2//num2 = $;System.out.println (num2); }}classFinaldemo { Public Static voidMain (string[] args) {Zi Z=NewZi ();    Z.show (); }}

Java Learning (vi) Object-oriented final keyword