EXCEPTION HANDLER action
| Function | Action defines a start of actions which handle an error (so called exception handler) and defines an area of their operation. |
| Declaration | EXCEPTION_HANDLER |
| Description | EXCEPTION_HANDLER action defines the start of actions which handle the error (so
called exception handler) and defines the area of their operation. According to context where the action is used, it can cause:
If EXCEPTION_HANDLER action is out of procedure it defines the exception handler for errors occurring in the actions of an initialization part of script and in initialization of the global variables. EXCEPTION_HANDLER action must not define the error handler for ON ERROR action. For example: |
PROCEDURE Proc2 ; incorrect placement of the command ON ERROR Error INT _i CALL Proc1 Error: EXCEPTION_HANDLER ; exception handling from the start of procedure to EXCEPTION_HANDLER action END Proc2 |
|
| When EXCEPTION_HANDLER action is executed, it is interpreted as RETURN action. Following two procedures are the same: | |
PROCEDURE Proc1 ; actions ; ..... RETURN EXCEPTION_HANDLER ; exception handling END Proc1 |
|
| or | |
PROCEDURE Proc1 ; actions ; ..... EXCEPTION_HANDLER ; exception handling END Proc1 |
|
| EXCEPTION_HANDLER action may handle the exceptions which occur while their are serviced: | |
PROCEDURE Proc3 ; actions ; .... EXCEPTION_HANDLER ; exception handling from start of procedure to EXCEPTION_HANDLER action EXCEPTION_HANDLER ; exception handling from the previous EXCEPTION_HANDLER action END Proc3 |
Related pages:
0 komentárov