Programming anecdotes-java null-in the land of tornadoes

1.null is a wonderful thing that can be understood as object placeholders

User user = null;

System.out.println (User.getcredits ());

can be compiled,

User user;

System.out.println (User.getcredits ()); but not .

when similar User user = null; such a variable goes to call only User user = new user (); to invoke the method, NullPointerException is triggered.

2. NullPointerException is also triggered when a null wrapper class is re-evaluated to the base type

Integer test = null;

int oop = test;

3. is null only possible to see?

Null can be strongly converted to any type of object and can be used to invoke a static method.

Programming anecdotes-java null-in the land of tornadoes