java 正则表达式检查数字中的数字是否全部相同或按顺序
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RegEx to check if the digits in a number are all the same or in sequence
提问by yyy
I want to check if the user's input in the server side. If the user enters a number 111111 or 22222 which has the same numbers, and also if the input is in sequence like 12345 or 456789.
我想检查用户在服务器端的输入。如果用户输入的数字 111111 或 22222 具有相同的数字，并且输入的顺序是 12345 或 456789。
回答by Susam Pal
To match consecutive same digits:
匹配连续的相同数字：
^([0-9])*$
Note that you have to escape the backslash when you put it in a java string literal, for example,
请注意，当您将反斜杠放入 java 字符串文字时，您必须对其进行转义，例如，
"^([0-9])\1*$"
For the second one you have to explicitly make a list of consecutive digits using the |operator. The regex would be really long and nasty with as many as 10-nested parantheses. One has to generate this regex using a program. In other words, this is a wrong problem to solve using regex. It would be much simpler to write a loop and test this.
对于第二个，您必须使用|运算符明确地制作一个连续数字列表。正则表达式将非常长且令人讨厌，其中包含多达 10 个嵌套的括号。必须使用程序生成此正则表达式。换句话说，这是使用正则表达式解决的错误问题。编写一个循环并测试它会简单得多。
回答by drf
This pattern will match if the user enters the same digit:
如果用户输入相同的数字，则此模式将匹配：
^(\d)*$
\1matches the first capture group, so the pattern matches whether that first digit is repeated for the entire string.
\1匹配第一个捕获组，因此模式匹配第一个数字是否在整个字符串中重复。
The second problem (consecutive digits) is somewhat more difficult.
第二个问题（连续数字）稍微困难一些。
^(?:^(?:^(?:^(?:^0?1)?2)?3)4?)?5(?:$|6(?:$|7(?:$|8(?:$|90?))))$|
^(0?1)?2(?:$|3(?:$|4))|^(6?7)?8(?:$|90?)$
is one implementation, assuming three or more digits. But since the number of combinations is small, enumerating (4+ digits) is also possible:
是一种实现，假设为三位或更多位数字。但是由于组合的数量很少，枚举（4+位）也是可能的：
^(?:0?123(45?)?|1?23456?|2?34567?|3?45678?|4?56789?|(5?6)?7890?|
(0?1)?2345678?(90$)?|1?23456789?|2?345678(90?)?)$
All this said, regular expressions don't always work well for this type of problem. A Java method to check for this sequence might be cleaner.
综上所述，正则表达式并不总是适用于此类问题。检查此序列的 Java 方法可能更简洁。
回答by JJoao
This time in perl, to explain the second case easier:
这次在 perl 中，更容易解释第二种情况：
perl -nlE 'say "BAD number" if ($_ =~ /^(\d)*$/ or "123456789" =~ /$_/)'
Explanation:
解释：
- case 1 : input ∈
/(\d)\1*/language: already presented ($_ =~ /^(\d)\1*$/) - case 2 : string "123456789" matches input (
"123456789" =~ /$_/)
- 情况 1 : 输入 ∈
/(\d)\1*/语言: 已经呈现 ($_ =~ /^(\d)\1*$/) - 情况 2：字符串“123456789”匹配输入 (
"123456789" =~ /$_/)
