Commodore Plus 4 - Page 24

12 The BASIC Language
Table 1-4. BASIC Abbreviations (continued)
Keyword
Abbreviation Keyword
Abbreviation
RENUMBER
RESTORE
RESUME
RETURN
RGR
RIGHTS
RLUM
RND
RUN
SAVE
SCALE
SCNCLR
SCRATCH
SGN
SIN
SOUND
SPC(
SQR
SSHAPE
renU
reS
resU
reT
rG
fl
rL
rN
rU
sA
scA
sC
scR
sG
si
sO
sP
sQ
sS
STEP
STOP
STR$
SYS
TAB(
TAN
THEN
TO
TRAP
TROFF
TRON
UNTIL
USING
USR
VAL
VERIFY
VOL
WAIT
WHILE
stE
sT
stR
sY
tA
—
tH
—
tR
troF
trO
uN
usi
uS
vA
vE
vO
wA
wH
Use the lowest possible line numbers. References to large line numbers take up
more memory than those to small line numbers. When you are writing the
program, it is smart to leave gaps between line numbers so you can easily add
lines. Once the program is finished, however, you can use the RENUMBER
command to change all the line numbers to lower, closer-together numbers.
Put multiple commands on a line. Separate commands on the same line with a
colon. There is no need to put spaces between the commands. Remember,
however, that each program line cannot exceed 88 characters in length.
Delete spaces between characters in the program lines. Although spaces
improve readability, they take up memory. Blanks are never required, so omit
them if you need to.
Remove REM statements if you need more room. Though useful for docu
menting a program, they do use up memory.
• Use variables in place of long numbers and calculations that are repeated in a
program.
> Use arrays to hold groups of data. Arrays, which are explained elsewhere in
this chapter, handle large groups of data as an organized list. If an array