Re^3: Deleting specific element in array in FOREACH loop

The downside is that
for my $index (reverse 0 .. $#array)
creates a list as large as the array, whereas
for (my $i = $#array; $i > -1; $i--)
and
for (my $i = @array; $i--; )
have no memory cost. That said, it usually doesn't matter.

On the plus side,
for my $index (reverse 0 .. $#array)
could be slower. It is optimized to loop backwards instead of actually calling reverse.

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Re^4: Deleting specific element in array in FOREACH loop by mreece (Friar) on Sep 15, 2006 at 20:15 UTC
for modern versions of perl, this is no longer true for normal ranges. does it still create the array for 'reverse' ranges?	[reply]
Re^5: Deleting specific element in array in FOREACH loop by ikegami (Patriarch) on Sep 15, 2006 at 21:47 UTC
Yes. In perl 5.8.6+, the `reverse` is optimized away, but the range is still flattened. I don't see anything in the perl588delta which says this has since changed. See lidden's Re^5: the '..' operator and decreasing values.	[reply] [d/l]