Java variable_2_Primitive Data type

Data type

In Java, there are different method of declaring variables for example,

• Integer Type
• Real Numbers
• Character
• Logic

For each type, there are different mothods.

For Interger type,

	byte	bit	range
byte	1	8	-128~127
short	2	16	-32,768~32,767
int	4	32	-2,147,483,648~2,147,483,647
long	8	64	-2^63~2^63-1

For Real Numbers,

	byte	bit	range
float	4	32	1.4x10^45~3.4x10^38
double	8	64	4.9x10^-324~1.8x10^308

There are range of errors too.

Float is most accurate under 6 decimal points while double is most accurate under 15 decimal points.

(Normaly, float is used to decrease the amount of memory used while running (such as making games). However, the computers' memory have increased dramatically during recent years, using double is recommended because its accuracy.)

 

For Character,

	byte	bit	range
char	2	16	0~2^16-1 (uni-code 0~65535)

For logic,

	byte	bit	range
boolean	1	8	true, false