Is there a way to change final variables, after they have been assigned?

Question

import java.util.Scanner;

public class OnlineShop {

  public static void main (String[]args) {

    final double subAmmount;

    subAmmount = subAmmount + Array[i];
}

The error:

The final local variable subAmmount may have already been assigned

Possible duplicate of [How does the "final" keyword in Java work? (I can still modify an object.)](https://stackoverflow.com/questions/15655012/how-does-the-final-keyword-in-java-work-i-can-still-modify-an-object) — ufoxDan, Nov 15 '19 at 03:23
The actual error this code gives is `variable subAmmount might not have been initialized`. — kaya3, Nov 15 '19 at 03:26

score 0 · Answer 1 · answered Nov 15 '19 at 03:34

0

"subAmmount" has not been initialized/set yet, so you cannot add subAmmount to itself, since it is not equal to anything.

answered Nov 15 '19 at 03:34

Ark1409

25
6

score -1 · Answer 2 · answered Nov 15 '19 at 03:33

Because subAmount is not declared as static, it must be initialized at the time of declaration. So you should have something like this

import java.util.Scanner;

public class OnlineShop {

  public static void main (String[]args) {

    final double subAmmount = Array[i]; // Assuming Array[i] is defined somewhere
}

If you'd like to do declaration followed by initialization, you'd do:

import java.util.Scanner;

public class OnlineShop {

  static final double subAmmount;

  public static void main (String[]args) {

    subAmmount = Array[i]; // Assuming Array[i] is defined somewhere
}

Checkout this link for more nuances on the final keyword

Is there a way to change final variables, after they have been assigned?

2 Answers2