Simple Data Types

Integers

byte      8-bit signed
short    16-bit signed
int      32-bit signed
long     64-bit signed

Floating-points

float    32-bit signed
double   64-bit signed

• Floating-point math never throws an exception.
• Dividing by 0 equals Inf.  // Infinity
• Dividing by Inf equals 0.

Characters

char     16-bit unicode

Booleans

boolean  true and false (only two possible values)

• Can't represent false as 0 or null.
• Can't represent true as nonzero.
• Can't cast from boolean to non-boolean, or vice versa.

Wrapper Classes

• Integer, Long, Float, Double, Boolean, Character.
• Can be used to convert values from one type to another.
• Can be used to pass simple data types by reference.

Misc

• Always uses the same amount of memory, regardless of compiler, processor, or platform.
• Passed by value to methods.
• Initialized by default to 0, null, or false.