Re^4: Merge 2 strings like a zip [unzip()]

You're welcome.

Regarding the for statement modifier, I think ++hexcoder has covered most of this in his response.

That's a fairly common Perl idiom that you're likely to see a lot. In fact, my usage wasn't the first in this thread: BrowserUk's zip() code has '... for split '', $b;'.

There's a bit more going on behind the scenes.

for iterates its list, aliasing $_ to each item in turn (see perlsyn: Statement Modifiers for details)
print defaults the filehandle to STDOUT and the list to the single item $_ (that's true in this case but an oversimplification nonetheless: see print for the full story)
The '-l' switch (on the shebang line) adds a "\n" to the end of each print statement (again, true in this case but still an oversimplification: see perlrun for the full details of '-l')

print for unzip('AaBbCcDdEeFGHIJ', 5);
[download]

is equivalent to

for (unzip('AaBbCcDdEeFGHIJ', 5)) {
    print STDOUT "$_\n";
}
[download]

-- Ken

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Re^5: Merge 2 strings like a zip [unzip()] by tel2 (Pilgrim) on Jul 10, 2015 at 00:39 UTC
Thanks for that explanation, Ken. I was aware of what "print for..." does (though I didn't realise some of the finer points you've mentioned), but I asked because I thought your code also worked without the 'for'. I now notice that the output without the 'for' has no newline between the returned arguments, i.e.: `ABCDEFGHIJabcde` which I assume is because it's just printing the 2 arguments (like a list) together. All that makes sense now though (I think), thanks. Sorry I wasn't clearer with my last question.	[reply] [d/l]
Re^6: Merge 2 strings like a zip [unzip()] by kcott (Archbishop) on Jul 10, 2015 at 04:35 UTC
No worries. And, yes, your assumption is correct. Alternatives might be `print join "\n", unzip('AaBbCcDdEeFGHIJ', 5);` [download] or the completely mad and hairy `{ local $" = "\n"; print "@{[unzip('AaBbCcDdEeFGHIJ', 5)]}"; }` [download] which, of course, you'd never consider doing, would you? :-) -- Ken	[reply] [d/l] [select]
Re^7: Merge 2 strings like a zip [unzip()] by tel2 (Pilgrim) on Jul 12, 2015 at 22:52 UTC
Thanks Ken. Correct - I would not do that. I does my head in.	[reply]