There are eight basic data types in Java: byte, short integer, integer, long, floating point, double precision, Boolean and character.

There are four integers, namely byte, short, int and long.

Corresponding to 8 bits, 16 bits, 32 bits and 64 bits. The range of values is -2 (number-1) ~ 2 (number-1)- 1 respectively.

Then define variables as: byte, short, int and long are all integer variables, and I think their encapsulation classes should also be integer variables. Bytes, short, integer, long.

Then everything else is a non-integer variable.