Mark Wickens

ON ERROR GOTO

Purpose

Specifies the line number to which execution branches when an error is generated.

Format

ON ERROR GOTO branch destination line number
              └─────────────┬──────────────┘
                        Line number 

Example

ON ERROR GOTO 1000

Parameters

branch destination line number: Integer in the range of 0 ≦ line number ≦ 65535

Explanation

1. Specifies the line number to which program execution branches when an error is generated. The program returns to normal operations when a RESUME statement is executed after the error handling routine (starting at the specified line number) is executed.
2. An error is generated and program execution is halted when the branch destination line number is 0.
3. An ON ERROR GOTO statement must be followed by a corresponding RESUME statement in the same program area. Branching to another program area using ON ERROR GOTO generates an error when the RESUME statement in the other program area is executed.

• The operations outlined are limited to BASIC program execution.

Sample Program

10  ON ERROR GOTO 40
20  **ERROR**
30  END
40  PRINT "OOPS! ERROR!!!": BEEP 1
50  RESUME 30

Execution of line 40, followed by line 30 if error generated. The program shown here is only an error subroutine and does nothing by itself.