Learn Java Tutorial 17 final keyword and overriding with example

This tutorial is made for learning about the final keyword and overriding with Example of Java Programming Language.

Final in java is very important keyword and can be applied to class, method, and variables in Java. In this java final tutorial we will see what is final keyword in Java, what does it mean by making final variable, final method and final class in java and what are primary benefits of using final keywords in Java and finally some examples of final in Java. Final is often used along with static keyword in Java to make static final constant and you will see how final in Java can increase performance of Java application.

Example of Final variable, Final method and Class in Java

What is final keyword in Java?

Final keyword, final variable, final method and class in java exampleFinal is a keyword or reserved word in java and can be applied to member variables, methods, class and local variables in Java. Once you make a reference final you are not allowed to change that reference and compiler will verify this and raise compilation error if you try to re-initialized final variables in java.

What is final variable in Java?
Any variable either member variable or local variable (declared inside method or block) modified by final keyword is called final variable. Final variables are often declare with static keyword in java and treated as constant. Here is an example of final variable in Java

public static final String LOAN = "loan";
LOAN = new String("loan") //invalid compilation error

Final variables are by default read-only.

What is final method in Java
Final keyword in java can also be applied to methods. A java method with final keyword is called final method and it can not be overridden in sub-class. You should make a method final in java if you think it’s complete and its behavior should remain constant in sub-classes. Final methods are faster than non-final methods because they are not required to be resolved during run-time and they are bonded on compile time.