What is a uninitialized reference variable when it's not null

Question

In java, local reference variables do not have a default value of null before they are initialized. What exactly is the difference between a variable with a value of null, and a variable with no value?

Answer 1

An uninitialized reference doesn't have no value, it has an undefined value (and the compiler prevents you from using them, IIRC). A reference initialized to null will result in a equality comparison with null always evaluating to true.