Commodore PET User Manual page 31

Special symbols can also be used as data characters, just Iike letters of
the alphabet. Consider the following examples:
Statement 1: PRINT "HI FRED, MARY. AND AL"
Statement 2: PRINT FR, MA, AL
ln the first statement. the commas are ordinary punctuation marks; they are
data characters just like ail the letters (and spaces) inside the quotation marks. In
facto every character occurring between the quotation marks is a simple text
character, which the BASIC interpreter treats as a text string. just as a typewriter
wou Id treat a keystroke.
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n statement 2, however, the commas are program opera-
tors; they are telling PET BASIC to use a special form of tabular alignment when
printing out values assigned to variables FR, MA. and AL.
Table 2-1 summarizes the meanings of the special symbols when they
are used as program opera tors. These usages are described in detail in Chapter
3.
Some of the special symbols do not have a program operator function. Such
symbols are merely graphie characters: they are used to create pictures on the
display screen. Some program operators are formed by combining special sym-
bols and/or letters of the alphabet just as vou combine letters into words. We will
describe these program operators later.
Special symbols and letters of the alphabet can have different meanings. de-
pending on where they appear in a BASIC statement. The word PRINT. for exam-
pie. is the part of a BASIC statement that tells the PET to print something. If the
same word were enclosed in quotes. it would be interpreted as a word of text.
Consider the aHirst confusing statement:
PRINT "PRINT"
The first PRINT is a command to print. but the second PRINT is a word of
text. or a string, because it is enclosed in quotes. What would this statement do?
You have probably already guessed -
it would print the word PRINT. (The
shaded portions in the screen examples show what you type in; the
unshaded portion is the PET's response):
PET BASIC doesn't just have homonyms - the same word having different
meanings: it also has synonyms - different words that have the same meaning.
For example, the command PRINT can be abbreviated to a question mark.
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