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carraysstatic

Variably modified array at file scope in C

I have some code like this:

static int a = 6;
static int b = 3;

static int Hello[a][b] =
{
    { 1,2,3},
    { 1,2,3},
    { 1,2,3},
    { 1,2,3},
    { 1,2,3},
    { 1,2,3}
};

But when I compile it, it says error:

variably modified 'Hello' at file scope

How could this happen? And how could I fix it?

Solution

  • You can not have a static array whose size is given as a variable.

    That's why constants should be #defined:

    #define a 6

    This way, the preprocessor will replace a with 6, making it a valid declaration.