Using The Colon - Commodore 128D User Manual

Below is a list of comparison symbols that may be used in the IF
statement and their meanings:
SYMBOL MEANING
EQUALS
> GREATER THAN
< LESSTHAN
<> NOT EQUALTO
> = GREATER THAN OR EQUAL TO
< = LESS THAN OR EQUAL TO
You should be aware that these comparisions work in expected
mathematical ways with numbers. There are different ways to deter
mine if one string is greater than, less than, or equal to another. You
can learn about these "string handling" functions by referring to
Chapter V, BASIC 7.0 Encyclopedia.
Section 5 describes some powerful extensions of the IF-THEN con
cept, consisting of BASIC 7.0 commands like BEGIN, BEND, and
ELSE.
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I )
I J
LJ
LJ
Using the Colon
A very useful tool in programming is the colon (:). You can use the
colon to separate two (or more) BASIC commands on the same line.
Statements after a colon on a line will be executed in order, from left
to right. In one program line you can put as many statements as you
can fit into 160 characters, including the line number. This is equiva
lent to four full screen lines in 40-column format, and two full lines in
80-column format. This provides an excellent opportunity to take
advantage of the THEN part of the IF-THEN statment. You can tell
the computer to execute several commands when your IF condition
is true. Clear the computer's memory, type in the following program
and RUN it.
10N=0
15N = N + 1
20 IF N<5 THEN PRINT N;"LESS THAN 5":GOTO 15
30 ? N; "GREATER THAN OR EQUAL TO 5"
40 END
52 USING C128 MODE—Advanced BASIC Programming