Final Keyword
Final
keyword can be used with class, variable and methods
Final class
Final
class cannot be extended i.e. creating subclass is not allowed for final class.
Example:
final class Student
{
// more code.
}
class Test extends Student // will create an compiler error
{
}
Final Method
Final
method cannot be overridden in its subclass. I.e. the method you have return
should be used as it in your subclass without changing it
Example:
public class Student { public int cube(int i) { return i * i * I; } }
Final variable
Final variable
or we call this as a constant, it cannot be changed in any part of your code. Final
keyword is applicable to all Example you can declare fields like
final float PI=3.14f;
Its good practice to add static keyword to a final member
variable since all object created for that class will be have a same value.
static final PI=3.14f;