是否有正则表达式匹配一串不断增加的连续数字，例如123,56789等？ 我不认为它可以在正则表达式，但值得在这里与人们核实。
答案 0 :(得分：6)
^(?:0(?=1|$))?(?:1(?=2|$))?(?:2(?=3|$))?(?:3(?=4|$))?(?:4(?=5|$))?(?:5(?=6|$))?(?:6(?=7|$))?(?:7(?=8|$))?(?:8(?=9|$))?(?:9$)?$
答案 1 :(得分：6)
^(1|^)((2|^)((3|^)((4|^)((5|^)((6|^)((7|^)((8|^)((9|^))?)?)?)?)?)?)?)?$
Python演示：
>>> import re
>>> good = ['1', '12', '123', '23', '3', '4', '45', '456', '56', '6', '7', '78', '789', '89', '9', '123456789']
>>> bad = ['a', '11', '13', '1345', '2459', '321', '641', '1 2', '222233334444']
>>> tests = good + bad
>>>
>>> regex = '^(1|^)((2|^)((3|^)((4|^)((5|^)((6|^)((7|^)((8|^)((9|^))?)?)?)?)?)?)?)?$'
>>> for test in tests:
... print '%s: %s' % (re.match(regex, test) and 'Passed' or 'Failed', test)
...
Passed: 1
Passed: 12
Passed: 123
Passed: 23
Passed: 3
Passed: 4
Passed: 45
Passed: 456
Passed: 56
Passed: 6
Passed: 7
Passed: 78
Passed: 789
Passed: 89
Passed: 9
Passed: 123456789
Failed: a
Failed: 11
Failed: 13
Failed: 1345
Failed: 2459
Failed: 321
Failed: 641
Failed: 1 2
Failed: 222233334444
答案 2 :(得分：4)
是否有正则表达式匹配一串不断增加的连续数字，例如123,56789等？
但当然，因为所有问题的答案开头，“是否有（Perl）正则表达式匹配......？”总是“为什么，当然还有！“操作性问题总是存在，” 是什么是匹配的Perl正则表达式？？“☺
Perl正则表达式就是这个：
m{
^ (
( \d )
(?(?= ( \d )) | $)
(?(?{ ord $3 == 1 + ord $2 }) (?1) | $)
) $
}x
如果通过具有两个不同的(?(COND)THEN|ELSE)条件组来工作，则将第1组的递归作为第二个的THEN子句。这就是(?1)的作用。
漂亮，嗯？
递归模式就像这些非常酷和非常强大; 这取决于你在良好的服务中使用这种力量，而不是邪恶。 ☺
我在下面给出的程序中使用了一种不那么聪明的形式。我将把另一个留在它开始的地方，这样你就可以在Perl 中看到它有多种方法来做它。
请注意，无论是什么 Unicode数字字符串，包括非ASCII（欢迎来到勇敢的新千年），甚至在Astral Plane中，语言都停留在UCS-2上，这都有效，有时甚至是UTF-16，甚至都无法思考。
此输出：
Yes: 3456
No: 43
Yes: 567
No: 1245
No: 568
No: 987
Yes: 12
Yes: 12345
No: 24
No: 13456
No: 12354678
Yes: 12345678
No: ١٣٠٢
Yes: ٤٥٦٧
No: २१३
Yes: ४५६७
Yes: ८९
No: ১১২
Yes: ৩৪৫৬
No: ৭৮৯৮
Yes: ௮௯
No: ௮௮
No: ๖๗๗๘
Yes: ๖๗๘
No: ༣༤༢༥༧༦༨
No: ０１１３２
Yes: ２３４
Yes: ８９
Yes:
No:
No:
Yes:
Yes:
Yes:
No:
Yes:
由该计划制作：
#!/usr/bin/env perl
use 5.10.0;
use utf8;
use strict;
use autodie;
use warnings qw< FATAL all >;
use open qw< :std :utf8 >;
use charnames qw< :full >;
# to iterate is human…
my @numbers = (
3456,
43,
567,
1245,
568,
987,
12,
12345,
24,
13456,
12354678,
12345678,
hard_stuff(),
);
my $ascending_rx = qr{
^ ( # works for *ANY* script!
( \p{Decimal_Number} )
(?= $ | (??{ chr(1+ord($2)) }) )
(?: (?1) | $ ) # …to recurse, divine!
) $
}x;
for my $n (@numbers) {
printf "%s: %10s\n",
($n =~ $ascending_rx) ? "Yes" : " No",
$n;
}
sub hard_stuff {
( "\N{ARABIC-INDIC DIGIT ONE}"
. "\N{ARABIC-INDIC DIGIT THREE}"
. "\N{ARABIC-INDIC DIGIT ZERO}"
. "\N{ARABIC-INDIC DIGIT TWO}"
),
( "\N{ARABIC-INDIC DIGIT FOUR}"
. "\N{ARABIC-INDIC DIGIT FIVE}"
. "\N{ARABIC-INDIC DIGIT SIX}"
. "\N{ARABIC-INDIC DIGIT SEVEN}"
),
( "\N{DEVANAGARI DIGIT TWO}"
. "\N{DEVANAGARI DIGIT ONE}"
. "\N{DEVANAGARI DIGIT THREE}"
),
( "\N{DEVANAGARI DIGIT FOUR}"
. "\N{DEVANAGARI DIGIT FIVE}"
. "\N{DEVANAGARI DIGIT SIX}"
. "\N{DEVANAGARI DIGIT SEVEN}"
),
( "\N{DEVANAGARI DIGIT EIGHT}"
. "\N{DEVANAGARI DIGIT NINE}"
),
( "\N{BENGALI DIGIT ONE}"
. "\N{BENGALI DIGIT ONE}"
. "\N{BENGALI DIGIT TWO}"
),
( "\N{BENGALI DIGIT THREE}"
. "\N{BENGALI DIGIT FOUR}"
. "\N{BENGALI DIGIT FIVE}"
. "\N{BENGALI DIGIT SIX}"
),
( "\N{BENGALI DIGIT SEVEN}"
. "\N{BENGALI DIGIT EIGHT}"
. "\N{BENGALI DIGIT NINE}"
. "\N{BENGALI DIGIT EIGHT}"
),
( "\N{TAMIL DIGIT EIGHT}"
. "\N{TAMIL DIGIT NINE}"
),
( "\N{TAMIL DIGIT EIGHT}"
. "\N{TAMIL DIGIT EIGHT}"
),
( "\N{THAI DIGIT SIX}"
. "\N{THAI DIGIT SEVEN}"
. "\N{THAI DIGIT SEVEN}"
. "\N{THAI DIGIT EIGHT}"
),
( "\N{THAI DIGIT SIX}"
. "\N{THAI DIGIT SEVEN}"
. "\N{THAI DIGIT EIGHT}"
),
( "\N{TIBETAN DIGIT THREE}"
. "\N{TIBETAN DIGIT FOUR}"
. "\N{TIBETAN DIGIT TWO}"
. "\N{TIBETAN DIGIT FIVE}"
. "\N{TIBETAN DIGIT SEVEN}"
. "\N{TIBETAN DIGIT SIX}"
. "\N{TIBETAN DIGIT EIGHT}"
),
( "\N{FULLWIDTH DIGIT ZERO}"
. "\N{FULLWIDTH DIGIT ONE}"
. "\N{FULLWIDTH DIGIT ONE}"
. "\N{FULLWIDTH DIGIT THREE}"
. "\N{FULLWIDTH DIGIT TWO}"
),
( "\N{FULLWIDTH DIGIT TWO}"
. "\N{FULLWIDTH DIGIT THREE}"
. "\N{FULLWIDTH DIGIT FOUR}"
),
( "\N{FULLWIDTH DIGIT EIGHT}"
. "\N{FULLWIDTH DIGIT NINE}"
),
#############################################
# Who's afraid of the astral planes?
# Try THIS, all you prisoners of UTF-16!
#############################################
( "\N{MATHEMATICAL BOLD DIGIT TWO}"
. "\N{MATHEMATICAL BOLD DIGIT THREE}"
. "\N{MATHEMATICAL BOLD DIGIT FOUR}"
. "\N{MATHEMATICAL BOLD DIGIT FIVE}"
),
( "\N{MATHEMATICAL BOLD DIGIT FIVE}"
. "\N{MATHEMATICAL BOLD DIGIT FOUR}"
. "\N{MATHEMATICAL BOLD DIGIT THREE}"
. "\N{MATHEMATICAL BOLD DIGIT TWO}"
),
( "\N{MATHEMATICAL DOUBLE-STRUCK DIGIT ONE}"
. "\N{MATHEMATICAL DOUBLE-STRUCK DIGIT TWO}"
. "\N{MATHEMATICAL DOUBLE-STRUCK DIGIT TWO}"
. "\N{MATHEMATICAL DOUBLE-STRUCK DIGIT THREE}"
),
( "\N{MATHEMATICAL DOUBLE-STRUCK DIGIT THREE}"
. "\N{MATHEMATICAL DOUBLE-STRUCK DIGIT FOUR}"
. "\N{MATHEMATICAL DOUBLE-STRUCK DIGIT FIVE}"
. "\N{MATHEMATICAL DOUBLE-STRUCK DIGIT SIX}"
),
( "\N{MATHEMATICAL SANS-SERIF BOLD DIGIT ONE}"
. "\N{MATHEMATICAL SANS-SERIF BOLD DIGIT TWO}"
. "\N{MATHEMATICAL SANS-SERIF BOLD DIGIT THREE}"
. "\N{MATHEMATICAL SANS-SERIF BOLD DIGIT FOUR}"
. "\N{MATHEMATICAL SANS-SERIF BOLD DIGIT FIVE}"
. "\N{MATHEMATICAL SANS-SERIF BOLD DIGIT SIX}"
. "\N{MATHEMATICAL SANS-SERIF BOLD DIGIT SEVEN}"
. "\N{MATHEMATICAL SANS-SERIF BOLD DIGIT EIGHT}"
. "\N{MATHEMATICAL SANS-SERIF BOLD DIGIT NINE}"
),
( "\N{MATHEMATICAL MONOSPACE DIGIT ZERO}"
. "\N{MATHEMATICAL MONOSPACE DIGIT ONE}"
),
( "\N{MATHEMATICAL MONOSPACE DIGIT TWO}"
. "\N{MATHEMATICAL MONOSPACE DIGIT THREE}"
. "\N{MATHEMATICAL MONOSPACE DIGIT FOUR}"
. "\N{MATHEMATICAL MONOSPACE DIGIT SIX}"
. "\N{MATHEMATICAL MONOSPACE DIGIT FIVE}"
),
( "\N{MATHEMATICAL MONOSPACE DIGIT THREE}"
. "\N{MATHEMATICAL MONOSPACE DIGIT FOUR}"
. "\N{MATHEMATICAL MONOSPACE DIGIT FIVE}"
. "\N{MATHEMATICAL MONOSPACE DIGIT SIX}"
. "\N{MATHEMATICAL MONOSPACE DIGIT SEVEN}"
. "\N{MATHEMATICAL MONOSPACE DIGIT EIGHT}"
. "\N{MATHEMATICAL MONOSPACE DIGIT NINE}"
),
}
答案 3 :(得分：2)
Perl：
my $prev = 0;
while($string =~ s/^\s*(\d+)\s*,\s*(.*)/$2/is) {
my $new = $1;
if($new > $prev) {
#NUMBERS ARE GETTING LARGER
} #if
else {
#NUMBER GOT SMALLERS
}
}