Java: Why am I required to initialize a primitive local variable?

Question

public class Foo {
    public static void main(String[] args) {
        float f;
        System.out.println(f);
    }
}

The print statement causes

Answer 1

Actually local variables are stored in stack.Hence there is a chance of taking any old value present for the local variable.It is a big challenge for security reason..Hence java says you have to initialise a local varible before use.