Commodore Plus 4 - Page 15

The Elements of BASIC 3
Data T^ypes
Floating-point numbers can be any type of number, whole or decimal (decimal
numbers are also called real numbers), between 2.93873588E-39 and
1.70141183E+38, the negatives of those numbers, or zero. Floating-point
numbers are stored in RAM using a 5-byte binary format.
Integer numbers can be any whole number between -32767 and 32767. (Note
that you can use larger and smaller values for floating-point numbers.) Numbers
with decimal parts are not accepted; they are truncated and ignored by BASIC.
Integer numbers are stored in RAM in a 5-byte binary format. Numbers in
integer arrays are stored as 2-byte binary numbers.
Character strings, or text strings, can be any characters in quotes, including
numbers, blank spaces, and special symbols. The only keyboard character that
cannot be directly included in a character string is a quotation mark. This is
impossible because a quotation mark is used to begin and end strings. If you try to
type a quotation mark in a string, BASIC assumes the quotation mark signifies
the end of the string; any additional characters are assumed to be a variable name.
For example, the command PRINT "HELLO" MOM prints HELLO 0. BASIC
prints the 0 as the value for what it assumes is the variable MOM. However, a
quotation mark may be used in a string with the help of the CHR$ function. Note
that a number in quotation marks is treated like any text and has no mathematical
value.
BASIC discriminates between these three data types in variable form by the
way you name the variable. The three variable types are shown in Table 1-1 with
the symbols used to distinguish them.
Floating-point variables can stand for any type of number, whole or decimal,
between 2.93873588E-39 and 1.70141183E+38, the negatives of those numbers,
or zero. Integer variables can stand for any whole number between -32767 and
32767. (Note that you can use larger and smaller numbers for floating-point
variables.) Numbers with decimal parts are not accepted. If you assign a decimal
number to an integer variable, the decimal part of the number is ignored. For
Table 1-1. BASIC Variable Types
Floatingpoint Integer Character String
Symbol None % $
Meaning Decimal or Whole numbers Characters
whole numbers only in quotes
Examples X, X5, RX X%, X5%, AGE% S$, R5$, NAMES