Atari XL

Programming 23
COST begins with COS. (See Appendix
1 for a full list of all the BASIC reserved
words.)
TYPES OF VARIABLE
There are two different types of variable, one
represents numbers, the other represents words.
The type which represents numbers is called the
numeric variable; the type representing words is
the string variable, so called because it contains a
sequence or (string' of characters. The variables in
the rectangle program were all numerical
variables.
Numeric Variables
These are used to represent numbers and can have
any value, whole numbers or fractions. Real
variables should be used in all arithmetical
programs. Real variables can have any value, for
example:
REAL = 3.72
SIZE = 87.3 * 2.5
String Variables
A string variable is used to store words, letters or
numbers. The variable name for a string variable
must be followed by a dollar sign ($) to distinguish
it from the a numeric variable. Examples are:
NAME$ = "WINSTON CHURCHILL"
STRING$
= "ABCDEFG"
Note that the letters defining the variable contents
are enclosed by quotation marks.
A string variable can hold almost any number of
characters, limited only by the amount of memory