QBasic 1.1: ON ERROR Statement



Description / Parameter(s)

GOTO line Branches to the first line of the error-handling routine, specified by a label or line number. To disable error handling, specify GOTO 0.
RESUME NEXT Resumes execution with the statement following the statement that caused the run-time error. Use the ERR function to obtain the error code for the error.
If ON ERROR isn't used, any run-time error ends your program.


'Illustrates ERDEV, ERDEV$, ERL, ERR, ERROR, ON ERROR, and RESUME. ON ERROR GOTO Handler 10 CHDIR "a:\" 'Causes ERR 71 "Disk not ready" 'if no disk in Drive A. 20 y% = 0 30 x% = 5 / y% 'ERR 11 "Division by zero." 40 PRINT "x% ="; x% 50 ERROR 57 'ERR 57 "Device I/O error." Handler: PRINT PRINT "Error "; ERR; " on line "; ERL SELECT CASE ERR CASE 71 PRINT "Using device "; ERDEV$; " device error code = "; ERDEV RESUME NEXT CASE 11 INPUT "What value do you want to divide by"; y% RESUME 'Retry line 30 with new value of y%. CASE ELSE PRINT "Unexpected error, ending program." END END SELECT