or download this
use strict;
use warnings;
...
Benchmark: timing 25000 iterations of For, Map...
For: 11 wallclock secs (10.62 usr + 0.00 sys = 10.62 CPU) @ 2355.16/s
+ (n=25000)
Map: 11 wallclock secs (11.18 usr + 0.00 sys = 11.18 CPU) @ 2236.94/s
+ (n=25000)