Strings - Commodore PET User Manual

Integers
An integer is a number that has no fractional portion or decimal point.
The number can be signed negative (-) or positive (+). An unsigned number is
assumed ta be positive. Integer numbers
have
a limited range of values. from
-32767 ta +32767. The following are examples of integers:
o
1
44
32699
-15
Any number that is an integer can also be represented in floating point for-
mat. since integers are a subset of floating point numbers. PET BASIC converts
any integers to floating point representation before doing arithmetic with
them. The most important difference between f10ating point numbers and in-
tegers is that an integer array uses less storage space in memory (two bytes
for an integer. versus five bytes for a floating point numberl.
STRINGS
We
have
already used strings as messages ta be printed on the display
screen. A string consists of one or more characters enclosed in double quota-
tion marks. Here are some examples of strings:
"HI!"
"SYNERGY"
"12345"
"$10.44 IS THE AMOUNT"
"22 UNION SQUARE. SAN FRANCISCO CA"
Ail of the data keys (alphabetic. numeric. special symbols. and graphies). as
weil as the three cursor control keys (Clear Screen/Home. Cursor Up/Down. Cur-
sor Lett/Rightl and the Reverse On/Off key can be included in a string. The only
keys that cannot be used within a string (besides the SHIFT key) are Run/Stop.
RETURN. and Insert/Delete.
Ali characters within the string are displayed as they appear. The cursor
control and Reverse On/Off keys. however. normally do not print anything them-
selves; to show that they are present in a string. certain reverse field symbols are
used. They are shown in Table 3-1.
When vou enter a string from the keyboard. it can
have
any length up ta the
space available within an 80-character line (that is. any character spa ces not
taken up by the line number and other required parts of the statement). However.
strings of up to 255 characters can be stored in the PET's memory. Vou get
long strings by pushing together, or concatenating, two separate strings to
form one longer string. We will describe this further when we discuss string
variables in general.
57