what is null in java code example

Example 1: What is null mean in java

When a reference variable doesn’t point to any value it is assigned null.
Example : Employee employee;
In the example employee object is not instantiate so it is 
pointed no where

Example 2: java checking for null

Objects.isNull(obj) //returns true if the object is null

Objects.nonNull(obj) //returns true if object is not-null

if(Objects.nonNull(foo) && foo.something()) // Uses short-circuit as well. No Null-pointer Exceptions are thrown.