Learning JavaScript by Ethan Brown

Author:Ethan Brown
Language: eng
Format: epub, pdf
Publisher: O'Reilly Media, Inc.
Published: 2016-03-01T05:00:00+00:00

try...catch...finally

There are times when the code in a try block involves some sort of resource, such as an HTTP connection or a file. Whether or not there is an error, we want to free this resource so that it’s not permanently tied up by your program. Because the try block can contain as many statements as you want, any one of which can result in an error, it’s not a safe place to free the resource (because the error could happen before we have the chance to do so). It’s also not safe to free the resource in the catch block, because then it won’t get freed if there is no error. This is exactly the situation that demands the finally block, which gets called whether or not there is an error.

Because we haven’t covered file handling or HTTP connections yet, we’ll simply use an example with console.log statements to demonstrate the finally block:

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.