Final arguments to function

Byron KiourtzoglouNovember 11th, 2012Last Updated: July 22nd, 2013

0 26 1 minute read

In this example we shall show you how to use final arguments to a function. To use final arguments to a function we have performed the following steps:

We have created class FinalArgs, that has run() method and a myFunc(final Calendar d) method.
The first method calls the second one, that uses a final Calendar argument and changes the Calendar.YEAR field.
We create a new instance of FinalArgs and call its run() method. The myFunc(final Calendar d) method is called and the attibute YEAR of final Calendar is changed.

If we try to change the calendar though an error will occur, since it is final and cannot be assigned to another value,

as described in the code snippet below.

package com.javacodegeeks.snippets.core;

import java.util.Calendar;

/**
 * Experiment with "final" args to functions (new in 1.1)
 */

public class FinalArgs {

    public static void main(String argv[]) {

  new FinalArgs().run();
    }

    void run() {

  System.out.println("Hummm...");

  myFunc(Calendar.getInstance());

  System.out.println("Once upon a time...");
    }

    void myFunc(final Calendar d) {

  // d = null;  // this will not compile

  d.set(Calendar.YEAR, 1999); // this will compile, and changes the object
    }
}

Output: