如何在正则表达式中获取命名组

问题描述

我有以下正则表达式列表

I have the following list of regular expressions

private List<Regex> _timeExtractionRegex = new List<Regex>()
        {
            new Regex(@"(?<hour>\d\d?):(?<minute>\d\d)\s?(?<meridiem>(a|p).?m)" , RegexOptions.IgnoreCase),
            new Regex(@"(?<hour>\d\d?)\s?(?<meridiem>(a|p).?m)" , RegexOptions.IgnoreCase),
            new Regex(@"(?<hour>\d\d?):(?<minute>\d\d)" , RegexOptions.IgnoreCase)
        }

第一个命名为群组 - 小时，分钟和meridiem。

第二个命名组 - 小时和meridiem。



问题这是从不同的来源发送给我的。如何获取命名捕获组的所有名称？

The first one has named groups - hour, minute and meridiem.
The second one has named groups - hour and meridiem.

The problem is that this is being sent to me from a different source. How do i get all the names of the named capture groups ??

推荐答案

引用：

如何获取指定捕获组的所有名称？

How do i get all the names of the named capture groups ??

int name;
var groupNames = _timeExtractionRegex.SelectMany(x=>x.GetGroupNames())
     .Where(n=>!int.TryParse(n, out name))
	 .Distinct().ToList();

请注意，GetGroupNames方法将返回未命名的组作为数字，如0,1,2等等，我已经添加了近似过滤掉这些组名的位置。

Note that GetGroupNames method will return unnamed groups as numerical numbers like 0,1,2 so on, I have added where close to filter out those group names.

string inputText = "12:45";
Regex regex = new Regex(@"(?<hour>\d\d?):(?<minute>\d\d)\s?(?<meridiem>(a|p).?m)", RegexOptions.IgnoreCase);
Match m = regex.Match(inputText);
string hour = m.Groups["hour"].Value;

如果你的意思是如何获得群组的鬃毛？，这也很简单：

If you mean "how do I get the manes of the groups?", that's pretty simple too:

Regex regex = new Regex(@"(?<hour>\d\d?):(?<minute>\d\d)\s?(?<meridiem>(a|p).?m)", RegexOptions.IgnoreCase);
string[] names = regex.GetGroupNames();

请注意，对于表达式中的两个未命名组，GroupNames数组将包含0和1，以及命名的组的名称。

Do note that the GroupNames array will contain "0" and "1" for the two unnamed groups in your expression, as well as the names of the named ones.

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