The Else Clause With If-Then; The Begin/Bend Sequence With If-Then - Commodore 128D User Manual

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The ELSE Clause with IF-THEN
The ELSE clause provides a way to tell the computer how to respond
if the condition of the IF-THEN statement is false. Rather than contin
uing to the next program line, the computer will execute the com
mand or branch to the program line mentioned in the ELSE clause.
For example, if you wanted the computer to print the square of a
number, you could use the ELSE clause like this:
Notice that you must use a colon between the IF-THEN statement
and the ELSE clause.
The BEGIN/BEND Sequence with IF-THEN
BASIC 7.0 allows you to take the IF-THEN condition one step further.
The BEGIN/BEND sequence permits you to include a number of pro
gram lines to be executed if the IF condition is true, rather than one
simple action or GOTO. The command is constructed like this:
IF condition THEN BEGIN:
(program lines):
BEND:ELSE
Be sure to place a colon between BEGIN and any instructions to be
executed and again between the last command in the sequence and
the word BEND. BEGIN/BEND can be used without an ELSE clause,
or can be used following the ELSE clause when only a single com
mand follows THEN. Try this program:
USING C128 MODE—Some BASIC Commands and Keyboard Operations Unique to
77 C128 Mode