Commodore Plus 4 - Page 51

Examples:
Example:
BASIC Version 3.5 Commands, Functions, and System Variables
39
DSAVE "BOXES"
90 DSAVE (A$),U9
EL
Stores the program BOXES onto the disk.
Stores a file onto the disk in drive unit 9. The
name of the file is the current value of A$. The
program is saved during execution.
Abbr. none
Determines the line number of the last BASIC error that occurred in a
program. Use PRINT EL to display the line number. The reserved variable EL is
often used in conjunction with the TRAP command, which isolates errors
without interrupting program execution.
ELSE
Abbr. eL
An optional clause you can add to an IF .
IF ... THEN . . . ELSE.
. THEN ... ELSE command. See
END
Abbr. eN
Ends a program with no message. You need to end a program with the END
command when subroutines or trap routines follow the body of the program.
You can also use END somewhere in the body of the program to terminate the
program if some condition is met.
50 IP A$="ST0P" THEN END Ends the program if A$ equals STOP.
ER Abbr. none
Determines the error number of the last BASIC error that occurred in a
program. Use PRINT ER to display the error number. The reserved variable ER
is often used in conjunction with the TRAP command, which isolates errors
without interrupting program execution. The BASIC errors are listed in Appen
dix A.
ERRS
ERRS (number)
Abbr. eR
Returns the error message describing the BASIC error number in parentheses.
The function ERRS is often used in conjunction with the TRAP command, which
isolates errors without interrupting program execution. To display the error
message for the most recent error in the program, type PRINT ERR$(ER).
Parameter: a numeric expression with value 1-36
The BASIC error messages are listed in Appendix A.