Constant Expression Required: why?

Question

I initialise a global array of Strings like so:

    private static final String[] foods = new String[]{"Pasta", "Beef", "Soup", "Chicken"};

And I use foods[0] in a switch statement. Says it requires a constant expression. What is not constant about this?

You can write `foods[0] = null;`. It's simply not a constant. — Andy Turner, Apr 22 '18 at 18:08
Possible duplicate of [Java switch statement: Constant expression required, but it IS constant](https://stackoverflow.com/questions/3827393/java-switch-statement-constant-expression-required-but-it-is-constant) — zython, Apr 22 '18 at 18:09

score 3 · Answer 1 · answered Apr 22 '18 at 18:10

3

The reference to the array, foods, is constant, but you could easily have written, somewhere in your program:

foods[0] = "abc";

Thus foods[0] is not a constant.

answered Apr 22 '18 at 18:10

Jim Garrison

I would mention that constant expressions are enumerated in https://docs.oracle.com/javase/specs/jls/se9/html/jls-15.html#jls-15.28 – Andy Turner Apr 22 '18 at 18:11
Okay - how do I fix it / what do I need to understand to be able to fix it? – Edwin Carlsson Apr 22 '18 at 18:11
@Edwin show us the switch. You can probably do it without the switch. Or, define the array elements using constants, and reference the constant in the switch. – Andy Turner Apr 22 '18 at 18:13

1 Answers1