I think, passing a string by reference makes sense when you work with extremely large strings. For example, if you were to store an entire image in raw uncompressed format in a string, then you better pass by reference lest you accidentally end up with copies in memory... Let's say you have a 4000x3000x24 image in memory. That's almost 40 megabytes. Now, if you read and write this string, you are better off if you pass by reference. Plus, you don't know who will run your script. Maybe someone will try to run it using an older Perl interpreter which does not have smart optimizations built into it. So, I think, it's safer when you're dealing with file contents or images or anything really big. Now, I've noticed that there is a slight toll in speed. Operations like substr($$REF, ...) are slightly slower than substr($STRING, ...) but it's negligible.

In reply to Re: Passing argument by reference (for a scalar) by harangzsolt33
in thread Passing argument by reference (for a scalar) by jmClifford

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