Wednesday, 16 November 2011

finally


When exceptions are thrown, execution in a method takes a rather abrupt, nonlinear path that alters the normal flow through the method. Depending upon how the method is coded, it is even possible for an exception to cause the method to return prematurely. This could be a problem in some methods. For example, if a method opens a file upon entry and closes it upon exit, then you will not want the code that closes the file to be bypassed by the exception-handling mechanism.

The finally keyword is designed to address this contingency.finally creates a block of code that will be executed after a try/catch block has completed and before the code following the try/catch block.

The finally block will execute whether or not an exception is thrown. If an exception is thrown, the finally block will execute even if no catch statement matches the exception. Any time a method is about to return to the caller from inside a try/catch block, via an uncaught exception or an explicit return statement, the finally clause is also executed just before the method returns. This can be useful for closing file handles and freeing up any other resources that might have been allocated at the beginning of a method with the intent
of disposing of them before returning.

The finally clause is optional. However, each try statement requires at least one catch or a finally clause.

Published by : Ruchita Pandya

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