Data Type	Java Keyword	Kind of Value	Bytes of Memory	Range of Values
Character	char	1 character - Unicode	2	not applicable
Byte	byte	integer	1	-128 to127
Short integer	short	Integers	2	-32,768 to 32,767 (-215 to 215 - 1)
Integer	int	Integers	4	-2,147,483,648 to 2,147,483,647 (-231 to 231 - 1)
Long Integer	long	Integers	8	-9223372036854775808 to 9223372036854775807 (-263 to 263 - 1)
Float	float	Decimal values to 7 decimal digit precision	4	3.4e-38 to 3.4e38  positive and negative
Double	double	Decimal values to 15 decimal digit precision	8	1.7e-308 to 1.73e308  positive and negative
Boolean	bool	Boolean (Logical) values True or False	1	not applicable

Rules for assigning variables: Assign short, int or long data types when you are sure a variable is a whole number (NO decimal points). Which type you choose depends upon the size of the numbers. Assign float or double when decimals are needed. Which type you choose depends upon the size of the numbers. Assign char if the variable will always contain only ONE character of data.