• Can be initialized when it is declared, in constructor or in static block

public class F
{
	private final String NAME = "Lin";
	private final int year;

	public F(int y)
	{
		year = y;
	}

	public String toString()
	{
		return NAME+": "+year;
	}

	public static void main(String args[])
	{
		final int SIZE = 10;

		//SIZE = 20;//not able to be changed

		F f = new F(2017);

		System.out.println(f);
	}
}
			

• final classes cannot be extended

public final class F
{
	private String name;

	public String toString()
	{
		return name;
	}
}
			

• Create Immutable Class
  • Class must be declared as final (So that child classes can’t be created)
  • Data members in the class must be declared as final (So that we can’t change the value of it after object creation)
  • A parameterized constructor
  • Getter method for all the variables in it
  • No setters(To not have option to change the value of the instance variable)

public final class Car
{
	private final String maker;
	private final String color;

	public Car(String m, String c)
	{
		maker = m;
		color = c;
	}

	public String getMaker()
	{
		return maker;
	}

	public String getColor()
	{
		return color;
	}
}
			

• Final method cannot be overridden
• Methods that are declared private are implicitly final
• Methods that are declared static are also implicitly final