Why use static blocks over initializing instance variables directly?

Question

Why would I use a static block:

static {
   B = 10;
}

over:

Integer B = 10;

What is the advantages/disadv

Answer 1

Actually, if you have

private static Integer B = 10;

The compiler will translate to, basically:

private static Integer B;
static {
    B = 10;
}

The thing with static blocks is that you can use the whole language and not just expressions to do initialisation. Imagine you need an array with a bunch of multiples of 7. You could do:

private static Integer[] array;
static {
    array = new Integer[1000];
    for (int i = 0; i < 1000; i++) {
        array[i] = 7 * i;
    }
}

Anyway, you could also do it this way:

private static Integer[] array = initArray();
private static Integer[] initArray() {
    Integer[] result = new Integer[1000];
    for (int i = 0; i < 1000; i++) {
        result[i] = 7 * i;
    }
    return result;
}