Introduction to Programming with Greenfoot: Object–Oriented Programming in Java™ with Games and Simulations, First Edition

Appendix D. Some Java details

Java data types

Java knows two kinds of types: primitive types and object types. Primitive types are stored in variables directly, and they have value semantics (values are copied when assigned to another variable). Object types are stored by storing references to the object (not the object itself). When assigned to another variable, only the reference is copied, not the object.

Primitive types

The following table lists all the primitive types of the Java language:

Type name	Description	Example literals
Integer numbers
byte	byte-sized integer (8 bit)	24	–2
short	short integer (16 bit)	137	–119
int	integer (32 bit)	5409	–2003
long	long integer (64 bit)	423266353L	55L
Real numbers
float	single-precision floating point	43.889F
double ...