Re: local vs. my

>>>>> "CD" == Chris Dolan <[email protected]> writes:

  CD> Ahh, I see -- cargo cult.  ;-)

  CD> Changing the topic a little bit...  I've always suspected there was a
  CD> speed difference between local and my.  So, I just benchmarked the
  CD> two versions, and "my" wins by a wide margin:

  CD> % perl test.pl
  CD>            Rate local    my
  CD> local 467290/s    --  -33%
  CD> my    699301/s   50%    --

makes perfect sense. my vars are not in the symbol table and just need
an initialization at run time and they exist in the pad of a sub. localized
vars need to save the previous value in some form of a stack (real work)
and also get initialized. so local should be slower. as for the cargo
cult, i agree. use local only when you MUST use it. mjd has a good
article on the 7 valid uses of local. just declaring vars in a sub is
not one of them.

uri

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