The final keyword indicates that a variable (identifier) can not change his value. In case the variable refers to a reference variable (an object) the values of variables inside (the object) can change but the reference can be reassigned (to another object).
A final function can not be overridden for any subclass. This means any class which extends our class with a final function can not redefine the functionality of our final function. if you have: public class Top{ public final doSomething(){ System.out.println("hi"); } } You can not do this: public class Buttom extends Top{ public final doSomething(){ // NO! YOU CAN'T CHANGE THIS FUNCTION System.out.println("good-bye"); // THIS CODE DOES NOT COMPILE } }
The final keyword in JAVA means that the class can no longer be derived, i.e. it cannot be used as a base class for a new child class.If you declare a method as final, this method cannot be overridden in any of the child class that may extend this class.
class is identifier
In Java, the final keyword specifies that the object created cannot be further redefined or derived.
The final keyword precedes a declared constant which after Instantiation cannot be modified. Examples. final double PI = 3.14; PI = 1234; // does not compile //or final double ONE; ONE = 1; // Instantiated ONE = 2; // does not compile ---------------------------------------- final keyword can also apply to a method or a class. When applied to a method - it means the method cannot be over-ridden. Specially useful when a method assigns a state that should not be changed in the classes that inherit it, and should use it as it is (not change the method behaviour). When applied to a class it means that the class cannot be instantiated. A common use is for a class that only allows static methods as entry points or static final constants - to be accessed without a class instance. A good example is Java's: public final class Math extends Object
yes of course... using the final keyword
By using the final keyword in the class declaration statement. Ex: public final class Test {...}
In the case of variables, the two can be combined. This occurs, for example, with the fields Math.PI and Math.E. I am not sure about methods, but I see no reason why you shouldn't be able to combine the two in this case.
When used in a class declaration, the final keyword means the a class can't be subclassed. In other words, no other class can extend (inherit) a final class, and any attempts to do so will give you a compiler error. The final keyword prevents a method from being overridden in a subclass. Final methods are usually placed in classes where you don't want anyone who is extending your code to meddle with a certain piece of functionality. Declaring a variable with the final keyword makes it impossible to reassign a different value to that variable once it has been initialized with an explicit value -
we cannot use the staic keyword inside the method... But we can use the final keyword inside the method....
It's a built-in keyword that defines an entity that cannot be later modified. It can be used in different aspects within your code (like setting a 'final' class, method (function), or variable).
The final keyword is used in several different contexts as a modifier meaning that what it modifies cannot be changed in some sense. public final class String This means this class will not be subclassed, and informs the compiler that it can perform certain optimizations it otherwise could not. It also provides some benefit in regard to security and thread safety. The compiler will not let you subclass any class that is declared final. You probably won't want or need to declare your own classes final though. You can also declare that methods are final. A method that is declared final cannot be overridden in a subclass. The syntax is simple, just put the keyword final after the access specifier and before the return type like this: public final String convertCurrency() You may also declare fields to be final. This is not the same thing as declaring a method or class to be final. When a field is declared final, it is a constant which will not and cannot change. It can be set once (for instance when the object is constructed, but it cannot be changed after that.) Attempts to change it will generate either a compile-time error or an exception (depending on how sneaky the attempt is). Fields that are both final, static, and public are effectively named constants.