Certain basic data types are built in to Java. These are:

Type	Description	bytes	Range of values
boolean	Boolean	1	false, true
byte	integers, very small	1	-128 to +127
short	integers, small ones	2	-32768 to +32768
int	integer	4	-2,147,483,648 to 2,147,483,647
long	integer, very big ones	8	+/-9.2*1018
float	floating point number	4	6 or 7 sig figs * 10 to +/- 38
double	floating point number very accurate	64	14 or 15 sig figs * 10 to +/- 38
char	character	4	Unicode character set

We will initially use just int, later char, boolean and if needed float.
String, which we will also use a lot is a class, not a primitive type.
Declaring a variable of a primitive data type reserves the appropriate storage in memory.

  int count;
  int height, width;
  char yearLetter;

Assignment (all primitive types)
This allows the assignment of a value to a variable

  count = 0;
  height = 12;
  width = height + 10;
  yearLetter = 'R';

Arithmetic (numeric types)
The four standard arithmetic operations of addition, subtraction, multiplication and division are given by the operators +, -, * and /
The modulus operator % gives the remainder of dividing an integer by an other integer e.g. 29%5 gives 4.
A unary minus - can be used to negate a value e.g. if count holds 7 then - count gives -7.
Post-increment and post-decrement operators ++ and -- increase and decrease a variable by 1. We will only use this operator as a statement e.g. if count holds 7 then

  count++;

is the same as

  count = count + 1;

Comparison operators (all primitive types)
The values of primitive types may be compared using the following operators; the result is always a boolean, either true or false.

operator	comparison	example
==	is equal to	count==10
!=	not equal to	height!=width
<	less than	height<width+10
<=	less than or equal to	height<=width+10
>	greater than	yearLetter>'L'
>=	greater than or equal to	yearLetter>='L'

Logical operators (boolean)
The boolean values and expressions are combined with the boolean operators:

operator	meaning	example
!	not	! ok
&&	and	heightOk && widthOk
||	or (inclusive)	heightError || widthError