Why is final the only modifier for local variables in Java?

Question

class Test {

    public static void main(String[] args) {
        private int x = 10;
        public int y = 20;
        protected int z = 30;
        static int w = 40;  
        final int i = 50;
    }
}

The only applicable modifier is final here; for other modifiers, the program gives compiler errors. Why is that? Please explain in detail.

Answer 1

In short - none of the other modifiers make sense in that context. Saying a variable is public, private, protected, or static simply doesn't make sense in the context of a local variable that will go out of scope (and be garbage collected) once the method exits. Those modifiers are intended for class fields (and methods), to define their visibility (or in the case of static, their scope).

final is the only one that makes sense in the context of a local variable because all it means is that the variable cannot be modified after its initial declaration, it has nothing to do with access control.