Type Wrappers

There is a division between primitive data types and the objects. The division sometimes needs to be crossed. For each primitive type, there is a corresponding wrapper class. A wrapper class can be used to convert a primitive data value into an object, and some type of objects into primitive data. The table shows primitive types and their wrapper classes. Case matters, so byte and Byte are different things.

primitive type	Wrapper type
byte	Byte
short	Short
int	Integer
long	Long
float	Float
double	Double
char	Character
boolean	Boolean

As an example, the value 103 could be held in 32 bit section of memory that is of primitive data type int. The same value could be held in an object that is of type Long. The object will use many more than 32 bits.

Don't worry if this all seems somewhat pointless to you right now. More will be said about wrapper classes later on when you need to use them.