Commodore PET - Read

Examples:
100 PRINT#1,A
200 PRINT#4,A$
300 PRINT#10.B%;",";C$
10
OPEN 1.1 ,2
20
PRINT#1,"HI"
55 OPEN 3,3
60
PRINT#3,"HI"
READ
Output numeric variable A and a
RETURN code to logical file 1.
Output string variable A$ and a
RETURN code to logical file 4.
Output numeric variable B%. a
comma, string variable
C$. and a
RETURN code to logical file 10.
Open cassette #1 for write.
Output HI to tape.
Open display screen.
Same
as ?"HI"
The
READ statement assigns values from a corresponding DATA statement
to variables named in the
READ list.
Format:
READ
where:
I
var
var, var,
... ,var
Read one data item.
Read multiple data items.
var
is a numeric or string variable.
READ is used to assign values to variables. READ can take the place of
multiple assignment statements
(see LET. .. =).
READ statements with variable lists require corresponding DATA state-
ments
with lists of constant values. READ does the actual assigning of data items
to the list of variables. On executing the first
READ statement in the pragram, the
first DATA constant
is assigned to the first READ variable. If the READ statement
has more than one variable listed. then the second DATA constant is assigned to
the second
READ variable. The assignments continue until ail of the READ varia-
bles in the
READ statement have been assigned values fram successive DATA
constants. A pointer
is maintained to the next available DATA constant. The next
READ always assigns the next DATA constant. The number of READ and DATA
statements can differ,
but there has to be an available DATA constant whenever a
READ statement is encountered. The data constants and corresponding variables
have to agree in type. A string variable can accept any specified constant; a
numeric variable can accept only numeric data.
There may
be more data than READ statements assigned; however, if the
end of the DATA statements
is reached before the end of the READ variables. the
program aborts
with an ?OUT OF DATA error message.
146