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Re: Callback



fixed

Thanks to all for taking the time to enlighten me.  I will surely take the time to better understand them.
 
Warmest Regards,

Richard Reeve


________________________________
From: Scott Klement <midrange-l@xxxxxxxxxxxxxxxx>
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Sent: Monday, October 15, 2012 5:04 PM
Subject: Re: Callback

Hi Richard,

Callbacks are extremely commonplace in computer programming. I'm kinda
shocked at seeing not one but multiple people in this thread saying that
they don't even know what a callback is.

Exit programs are an example of a callback. You give the system the name
of a program, and it calls it at a particular time.

Triggers are another.

The %HANDLER routines used by XML-SAX or XML-INTO are callbacks.

APIs like Qp0lProcessSubtree(), QaneSava, QaneRsta use callbacks.

I use callbacks in RPG, C, Java, JavaScript.  In fact, in JavaScript
they are utterly ubiquitous, you can't sneeze without using a callback
in JavaScript.

You should definitely take the time to learn about them.


On 10/15/2012 3:50 PM, Richard Reeve wrote:
Has anyone ever heard of a callback as it is related to the IBM i?  I was asked to explain a callback during an interview and I'd never even heard of it.  Can any of you explain to me what a callback is and how it is used?  I tried google but didn't get a good explanation.

Thanks.

Warmest Regards,

Richard Reeve






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