User`s manual

4-15
REM
Instructs the Computer to ignore the rest of the program line. This allows you
to insert comments (REMarks) into your program for documentation. Then,
when you (or someone else) look at a listing of your program, it'll be a lot
easier to figure out. If REM is used in a multi-statement program line, it
must be the last statement.
Examples Program:
10 REM ** THIS REMARK INTRODUCES THE PROGRAM **
20 REM ** AND POSSIBLY THE PROGRAMMER, TOO. **
30 REM ** **
40 REM ** THIS REMARK EXPLAINS WHAT THE **
50 REM ** VARIOUS VARIABLES REPRESENT: **
60 REM ** C = CIRCUMFERENCE R = RADIUS **
70 REM ** D = DIAMETER **
80 REM
90 INPUT"RADIUS";R: REM THIS IS FIRST EXECUTABLE LINE
The above program shows some of the graphic possibilities of REM
statements. Any alphanumeric character may be included in a REM
statement, and the maximum length is the same as that of other statements:
255 characters total.
IN LEVEL II BASIC, an apostrophe '(SHIFT 7) may be used as an
abbreviation for: REM.
100 'THIS TOO IS A REMARK
IF
true/false expression
THEN
action-clause
Instructs the Computer to test the following logical or relational expression.
If the expression is True, control will proceed to the "action" clause
immediately following the expression. If the expression is False, control will
jump to the matching ELSE statement (if there is one) or down to the next
program line. In numerical terms, if the expression has a non-zero value, it is
always equivalent to a logical True. Examples:
100 IF X>127 THEN PRINT "OUT OF RANGE": END
If X is greater than 127, control will pass to the PRINT statement and then to
the END statement. But if X is not greater than 127, control will jump down
to the next line in the program, skipping the PRINT and END statements.