created: 02/15/98; revised: 07/31/99, 01/18/00, 06/01/00, 05/11/03, 01/13/06

The Java primitive types include the
floating point types `float`

and `double`

.
Floating point numbers are those that include a fractional part.
When written for human viewing, a floating point number includes a decimal point.
For example, `3.14159`

and `-0.718802`

.

- Converting strings to double
- Keyboard input of floating point numbers
- The Math class
- Square root
- Trig functions
- PI
- Not a Number (NaN)

All of the familiar mathematical functions such as
*sine*, *log*, and *square root*
are available to your program in the Java `Math`

class.
These functions typically expect floating point data.

Which uses more bits: a Java `float`

or a a Java `double`

.