#!/usr/bin/perl use strict; use warnings; use Benchmark qw /cmpthese timethese/; our $size = 100_000; cmpthese timethese( -10 => { push => 'my @arr; push @arr => $_ for 0 .. $::size - 1', assign => 'my @arr; $arr [$_] = $_ for 0 .. $::size - 1', assignpre => 'my @arr; $#arr = $::size - 1; $arr [$_] = $_ for 0 .. $::size - 1', assignlast => 'my @arr; $arr[ $::size - 1 ] = undef; $arr [$_] = $_ for 0 .. $::size - 1', slice => 'my @arr; @arr [0 .. $::size - 1] = (0 .. $::size - +1)', slicepre => 'my @arr; $#arr = $::size - 1; @arr [0 .. $::size - 1] = (0 .. $::size - +1)', slicelast => 'my @arr; $arr[ $::size - 1 ] = undef; @arr [0 .. $::size - 1] = (0 .. $::size - +1)', } => 'none' ); __END__ Rate slicepre slice slicelast assignpre assign assignlast push slicepre 124/s -- -10% -11% -21% -27% -28% -35% slice 138/s 11% -- -0% -12% -19% -20% -28% slicelast 138/s 12% 0% -- -11% -18% -20% -28% assignpre 156/s 26% 13% 13% -- -8% -9% -19% assign 169/s 37% 23% 22% 8% -- -2% -12% assignlast 172/s 39% 25% 24% 10% 2% -- -10% push 192/s 55% 39% 39% 23% 13% 11% -- ## Same comparisons node 209382 on my machine (maybe bit more apples to apples) Rate slicepre slice assignpre assign push slicepre 123/s -- -10% -21% -25% -36% slice 137/s 11% -- -12% -17% -29% assignpre 156/s 27% 14% -- -5% -19% assign 165/s 34% 20% 6% -- -14% push 192/s 56% 40% 23% 17% --