Java / final keyword

The final keyword can be used with a class, method, and variables.

With class, it prevents inheritance by not allowing to create subclasses.

With methods, it prevents overriding, you cannot override a final method in Java.

With variable, it is treated as constant because you cannot change their value once assigned.

Yes, you can make an array final in Java and you can change it's elements as well. Both array and collection classes can be made final and you can still change their elements.

The abstract method is incomplete while the final method is regarded as complete. The only way to use an abstract method is by overriding it, but you cannot override a final method in Java.

Yes, you can overload a final method in Java.

Yes, you can make a static method final in Java.

When we declare a static method as final its prevents from method hiding and encounters compile time error: Cannot override the final method from Parent.

public class Parent {

	final static void helloWorld() {

		System.out.println("Hello from Parent.");
	}

}

class Child extends Parent {

	// compile error : Cannot override the final method from Parent
	static void helloWorld() {

		System.out.println("Hello from child.");
	}

}

No. It is not possible.

No, not possible. final implies that the method is complete and cannot be overridden whereas abstract marks an incomplete method and needs to be overridden.

No, you cannot override a final in Java.

Non-static final variable can be initialized when declared or in constructor only. Otherwise we will encounter compilation error.

Static final variable can be initialized where it is declared or using static block.

A final variable declared but not assigned is known as a blank final variable. It can be initialized within a constructor only. It raises a compilation error if it is not initialized.

It is a blank final variable declared as static. That is, a final static variable declared but not given a value or not initialized is known as a static blank final variable. It can be initialized through a static block only.

Java finally block is used to execute important code such as closing connection, stream etc.

It is always executed whether exception is handled or not. Java finally block follows try or catch block.