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What is final class in Java with examples?
When a class is declared with final keyword, it is called a final class. A final class cannot be extended(inherited). There are two uses of a final class: Usage 1: One is definitely to prevent inheritance, as final classes cannot be extended. For example, all Wrapper Classes like Integer, Float, etc.
What does final mean in Java?
In the Java programming language, the final keyword is used in several contexts to define an entity that can only be assigned once. Once a final variable has been assigned, it always contains the same value.
How do you call a final class in Java?
1) Java final variable
- class Bike9{
- final int speedlimit=90;//final variable.
- void run(){
- speedlimit=400;
- }
- public static void main(String args[]){
- Bike9 obj=new Bike9();
- obj.run();
What is a final class?
A final class is a class that can’t be extended. Also methods could be declared as final to indicate that cannot be overridden by subclasses. Preventing the class from being subclassed could be particularly useful if you write APIs or libraries and want to avoid being extended to alter base behaviour.
What is the use of final?
The final keyword is a non-access modifier used for classes, attributes and methods, which makes them non-changeable (impossible to inherit or override). The final keyword is useful when you want a variable to always store the same value, like PI (3.14159…). The final keyword is called a “modifier”.
How do I make my class final?
To specify that your class is final, use the keyword final before the class keyword in your class declaration. For example, if you wanted to declare your (perfect) ChessAlgorithm class as final, its declaration should look like this: final class ChessAlgorithm { }
Why are final classes used?
The main purpose of using a class being declared as final is to prevent the class from being subclassed. If a class is marked as final then no class can inherit any feature from the final class. You cannot extend a final class. If you try it gives you a compile time error.
Can we make class final in Java?
A class can be made final by using the final keyword. The final class cannot be inherited and so the final keyword is commonly used with a class to prevent inheritance.
What is super () in Java?
The super() in Java is a reference variable that is used to refer parent class constructors. super can be used to call parent class’ variables and methods. super() can be used to call parent class’ constructors only.
What are final classes in Java?
A final class cannot be subclassed. As doing this can confer security and efficiency benefits, many of the Java standard library classes are final, such as java.lang.System and java.lang.String.
What does final do in Java?
final in Java. final keyword in java has its usage in preventing the user from modifying a field, method or class. final field- A variable declared as final prevents the content of that variable being modified. final method- A method declared as final in Java prevents the user from overriding that method.
How does the “final” keyword in Java work?
Final Variables Declaring a variable as final means restricting any alteration to the value of the variable in the inherited classes.