Catch[expr]returns the argument of the first Throw generated in the evaluation of expr.
Catch[expr,form]returns value from the first Throw[value,tag] for which form matches tag.
Exit to the enclosing Catch as soon as the Throw is evaluated:
Define a function that can "throw an exception":
The result of the Catch is just what is thrown by Throw:
Use Throw to exit a loop when a criterion is satisfied:
Throw Check CheckAbort Reap