为什么两个打印的数字不同？
#!/usr/bin/env perl
use warnings;
use 5.10.1;
my $sep = '';
my $number = 110110110110111;
$number =~ s/(\d)(?=(?:\d{3})+\b)/$1$sep/g;
say "A: <$number>";
$number =~ s/\Q$sep\E//g;
say "B: <$number>";
输出：
A: <110110110110111> B: <11111111111>
解决方法
报价
man perlop：
If the pattern evaluates to the empty string,the last successfully
executed regular expression is used instead.
尝试在第二次替换之前插入一个成功的正则表达式匹配,看看发生了什么：
(my $foo = '1') =~ s/1/x/; # successfully match “1” $number =~ s///g; # now you’re deleting all 1s say "B: <$number>"; # <0000>
我会说这应该被弃用,并且通过使用警告来警告,很难看到好处.