Ignore this. I completely missed the point (asynchronous). Sorry. I'll update later when I've eaten.

Think about grep.

Grep is a generic routine that filters one list (which may come from an array) into another list (which may be assigned to an array).

The callback defines how it filters the list.

So, with no changes to the implementation of grep, this filters out even numbers: my @odds = grep{ ( $_ % 2 ) == 1 } 1 .. 100;

and this filters out the odd numbers: my @evens = grep{ ( $_ % 2 ) == 0 } 1 .. 100;

The callbacks: { ... }, allow a generic routine to perform multiple purposes.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority". I'm with torvalds on this
In the absence of evidence, opinion is indistinguishable from prejudice. Agile (and TDD) debunked

In reply to Re: Understanding callbacks by BrowserUk
in thread Understanding callbacks by stevieb

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