Initialize array at compile time

Question

foo is a global array of integers that must be initialized. If, in a future, I change SIZE to 6 then I will have to add MANUALLY two new INIT_VALUE items to the initialization list. Is there a macro or other thing that could be used to modify automatically the initialization list at compile time when the value of SIZE is changed?

#define SIZE 4
#define INIT_VALUE 101

/* global variable that must be initialized */
int foo[SIZE] = {INIT_VALUE, 
                 INIT_VALUE, 
                 INIT_VALUE, 
                 INIT_VALUE};

http://stackoverflow.com/questions/201101/how-to-initialize-an-array-in-c — Theemathas Chirananthavat, Dec 04 '11 at 13:56
http://stackoverflow.com/questions/201101/how-to-initialize-an-array-in-c — Theemathas Chirananthavat, Dec 04 '11 at 14:03

score 1 · Answer 1 · answered Apr 23 '11 at 11:08

1

If this INIT_VALUE is not 0, you can't initialize the array in the way you mentioned (to support unknown elements). I don't think there's even such an option to implement it using macros, probably the correct way to do it is a loop to initialize (in function) the array (memset will not help either if your value doesn't look like 0xYXYXYXYX (all bytes are the same))

answered Apr 23 '11 at 11:08

MByD

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The problem is that foo is a global variable that must be initialized before using any function of the module, so using a function to initilize it is not an option. – Fernando Apr 23 '11 at 13:37
@Fernando - the problem is that you can't. You have two options: 1. initialize it in a function (Maybe init of the module) 2. modify the source each time hat `size` changes. – MByD Apr 23 '11 at 15:35

Initialize array at compile time

1 Answers1