regex - 如何在 perl 中将字符串的字母和数字分开？

Question

使用 split() 拆分字符串并从该字符串创建一个数组，使单词和数字分开。

我知道前瞻和后视需要用于零宽度分割，所以我使用了它。

$string = 'A1BB22CCC333DDDD';
@string = split(/(?=\d+)|(?<=\d+)/,$string);
print "@string";

期望:

A 1 BB 22 CCC 333 DDDD

但是结果:

Variable length lookbehind not implemented in regex m/(?=\d+)|(?<=\d+)/ at jdoodle.pl line 2.

Command exited with non-zero status 255.

Answer 1

您可以使用类似 /(\d+)/ 的模式来拆分字符串。

该模式包含一个捕获组；如 perldoc split 中所述:

If the PATTERN contains capturing groups, then for each separator, an additional field is produced for each substring captured by a group (in the order in which the groups are specified, as per backreferences);

考虑:

use strict;
use warnings;
my $string = "A1BB22CCC333DDDD";
my @result = split /(\d+)/, $string;
print "$_\n" for @result;

产量:

A
1
BB
22
CCC
333
DDDD

---

如果字符串以数字开头，上述解决方案将返回一个前导空元素。为避免这种情况，您可以按如下方式调整表达式:

my @result = grep length, split /(\d+)/, $string;