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Qus:- What is the final keyword in Java?

19th May 2019, 9:51 AM
Deepika Mourya
Deepika Mourya - avatar
6 Respostas
+ 12
final is a keyword used to make a variable constant. Like final float Pi=3.14; This will declare a constant named Pi which is equal to 3.14. If you will try to change the value of this constant , you'll get an error
19th May 2019, 9:56 AM
Siddharth Golecha
Siddharth Golecha - avatar
+ 3
final keyword in Java can be used in many context. final can be: 1. final variable 2. final method 3. final class 1) final variable - to create constant variables 2) final method - to prevent method overloading 3) final class - to prevent inheritance
19th May 2019, 11:15 AM
Vaishnavi Rajkumar Pawar
+ 3
1)final variable: 1. When a variable is declared with a final keyword, it's value cannot be modified. 2. Means by using final keyword, the variable becomes constant. 3. This also means you must initialize a final variable. 4. final variable cannot be inherited. Example: class Test { public static void main(String args[]) { final int i =10; i=30; } } Output: Error- Cannot assign a value to final variable i i=30
19th May 2019, 11:20 AM
Vaishnavi Rajkumar Pawar
+ 3
2) final method: 1. A final method cannot be overridden. 2. Which means even the subclass can call the final method of parent class without any issues but it cannot override it. Example: final void show() { }
19th May 2019, 11:22 AM
Vaishnavi Rajkumar Pawar
+ 3
3) final class: 1. The final class is complete in nature and cannot be subclassed or inherited. 2. Several classes in Java are final like String, Integer and other Wrapper classes. Example: final class Exam { } class Test extends Exam { public static void main(String args[]) { Test t1=new Test(); } } Output: Error- Cannot inherit from final class
19th May 2019, 11:26 AM
Vaishnavi Rajkumar Pawar