substr($s, 0, 3) = "abc"
$s =~ s/.../abc/s
Which is faster?
my $N = shift || 1000000; my $s = shift || "The quick brown fox jumps over the lazy dog";
my ($su, $ss) = times;
for (1 .. $N) { substr($s, 0, 3) = "abc" }
my ($eu, $es) = times;
my ($tu, $ts) = ($eu - $su, $es - $ss);
my $total = $tu + $ts;
printf "%20s %5.2f %5.2f %6.2f\n", "substr", $tu, $ts, $total;
my ($su, $ss) = times;
for (1 .. $N) { $s =~ s/.../abc/s }
my ($eu, $es) = times;
my ($tu, $ts) = ($eu - $su, $es - $ss);
my $total = $tu + $ts;
printf "%20s %5.2f %5.2f %6.2f\n", "regex", $tu, $ts, $total;
The output:
substr 5.04 0.01 5.05 regex 5.71 0.00 5.71