try Statement

try ... catch ... end try blocks are how errors are handled in TMBASIC. Errors are raised using the throw statement. If an error is raised inside a try block, then program execution will jump to the catch block in order to handle the error. You can display the error to the user or take some other corrective action like retrying. Use rethrow in your catch block to re-raise an error that you want to pass up to the calling code.

Syntax

• <TRY-STATEMENTS> is the code to execute that may potentially fail with an error.
• <CATCH-STATEMENTS> is the code to execute if an error is raised inside the try block. It will not be executed if the try block executes successfully.

Usage

The following example is contrived to show both the "thrower" and "catcher" sides of a raised error. The message string provided to the throw statement can be retrieved from the ErrorMessage function inside your catch block. The ErrorCode function can be used to retrieve the error code, which is optional for your own throw statements but is always available for TMBASIC-generated errors.In real code, the throw statement will be inside a function or subroutine, and the catch block will be in the calling code.