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Re^2: map vs for\foreach.

by builat (Monk)
on Mar 11, 2015 at 14:38 UTC ( #1119645=note: print w/replies, xml ) Need Help??


in reply to Re: map vs for\foreach.
in thread map vs for\foreach.

In my case:
foreach(@a){$_+=1;}; real 0m3.756s user 0m3.588s sys 0m0.120s

map{$_+= 1} @a; real 0m5.233s user 0m5.056s sys 0m0.164s

Replies are listed 'Best First'.
Re^3: map vs for\foreach.
by sn1987a (Chaplain) on Mar 11, 2015 at 15:12 UTC

    My previous timings where just from a single run of each program. Using Benchmark and repeating to verify consistent results, I find that foreach is indeed faster.

    use strict; use warnings; use Benchmark; my @a; $a[$_] = int( rand(100) ) for ( 0 .. 10000000 ); cmpthese( -30, { 'foreach' => sub { foreach (@a) { $_ += 1; } }, 'map (assign)' => sub { @a = map { $_ += 1 } @a; }, 'map (bare)' => sub { map { $_ += 1 } @a; }, } );

    Results:

    s/iter map (assign) map (bare) foreach map (assign) 2.06 -- -40% -76% map (bare) 1.23 67% -- -59% foreach 0.501 311% 146% --

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