In Java, the final is keyword use with class, method, and variables. When it combined with one of these having below side effects on compile time:

• A final class can not be instantiated.
• A final method can not be overridden.
• A final variable can not be re-assigned.

See Also: Difference between final, finally and finalize

final keyword Example

A final variable can not be re-assigned.

A final class can not be subclassed.

A final method can not be overridden.