September 14, 2002 - Throwing Exceptions | WebReference

September 14, 2002 - Throwing Exceptions

Yehuda Shiran September 14, 2002
Throwing Exceptions
Tips: September 2002

Yehuda Shiran, Ph.D.
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Sometimes you cannot handle a specific error in the catch block associated with the try block where the error occurred. In this case, use the throw statement to re-throw the error to higher-level error handling. A try...catch...finally statement may be nested within a higher-level try statement. When you throw an exception from a lower-level catch block, it will be caught by the higher level catch block. The syntax is very simple:

  throw exception
where exception is any expression and is required. It can be a string or an Error object. The exception value is simply passed as a parameter to the catch block. If the throw statement is inside a try block, the exception value is passed to the corresponding same-level catch block. If the throw statement is inside a catch block, the exception value is passed to the higher-level catch block, if one exists.

To learn more about exception handling, go to Column 118, JScript .NET, Part XII: Exception Handling.