What is null in java

Question

What does it mean?

Answer 1

In java, a variable is a reference to an object. A null value thus indicates an unset reference (i.e. a reference to nothing). You can see variables as containers(*), inside which you can put an object of a given type, when the variable is null, it means your container is empty.

Answer 2

"null" is a reference type and its value is the only reference value which doesn't refer to any object. There is no representation of null in memory. The binary value of a reference-typed variable whose value is null is simply zero. Even though this is not explicitly specified, it follows from the general initialization semantics of objects and any other value would cause major problems to an implementation