Debugging and Error-Handling Language

Article
06/18/2008

The following table lists language makes it possible for you to perform debugging and error-handling operations in Visual FoxPro programs.

Debugging Language

Use	To
* Command	Indicate the beginning of a comment line.
&& Command	Indicate the beginning of an inline comment.
CLEAR Commands	Release the specified item or items from memory.
DEBUG Command	Open the Visual FoxPro Debugger.
DEBUGOUT Command	Direct the result of one or more expressions to the Debug Output window.
SET DEVELOPMENT Command	Determine whether the Trace window is opened when an error occurs in a form that is running.
SET TALK Command	Determine whether Visual FoxPro displays command results.
SET TRBETWEEN Command	Enable or disables tracing between breakpoints in the Trace window.
WAIT Command	Display a message and pauses Visual FoxPro execution until the user presses a key or clicks the mouse.

Error Handling Language

Use	To
AERROR( ) Function	Store error information in an array.
COMRETURNERROR( ) Function	Store error information in the COM exception structure.
DEBUG Command or SET STEP Command	Open the Debugger or Trace window.
ERROR Command	Generate a specific Visual FoxPro error to test your error handling.
ERROR( ) Function	Return an error number.
LINENO( ) Function	Return an executing program line.
MESSAGE( ) Function	Return an error message string.
ON ERROR Command	Execute a command when an error occurs.
ON( ) Function	Return commands assigned to error handling commands.
ON SHUTDOWN Command	Executes a command when exiting Visual FoxPro or Windows.
PROGRAM( ) Function OR SYS(16) - Executing Program File Name	Return the name of the currently executing program.
RETRY Command	Run the most recently executed command.
SET AUTOINCERROR Command	Generate an error when attempting to update or insert values in an autoincrementing field.
SYS(2018) - Error Message Parameter	Return any current error message parameter.
SYS(2410) - Error Handler	Return error handler type for an error.
TRY...CATCH...FINALLY Command	Handle errors and exceptions that might occur while running a block of code.

See Also

Reference

Debugger Window

Other Resources

Testing and Debugging Applications

Language Categories