在C＃中使用正则表达式提取字符串

Question

I have this string in C#: "/19/Ora01" and i want to exctract "Ora01"

I have tried with no success:

var pattern = @"^(Ora[0-9]{2})$";

var match = Regex.Match(args.Path, pattern);

var hour = match.Groups[0].Value;

What I'm doing wrong?

What about to exctract two other strings, one with 19, the other with Ora01?

Answer 1

如果您将/ Split() / Split() /如果字符串为/19/Ora01模式，该/19/Ora01

var data = "/19/Ora01".Split("/", StringSplitOptions.RemoveEmptyEntries);

Answer 2

This is what you want with Regex:

public static void Main(string[] args)
  {
    string pattern = "\\/(.*?)\\/(.+)";
    string text = "/19/Ora01";
    Match match = Regex.Match(text, pattern);
    string first = match.Groups[1].Value;
    string second = match.Groups[2].Value;

    Console.WriteLine(first);
    Console.WriteLine(second);

    Console.ReadLine();
  }

Consider also the answer provided by Rahul .

Answer 3

^ means "start of string" and "$" means "end of string. You asked for something that contains only Ora followed by two digits. Remove ^ at least. You don't need grouping either. Ora[0-9]{2} should work :

var pattern = @"Ora[0-9]{2}";

var match = Regex.Match("/19/Ora01", pattern);

var hour = match.Groups[0].Value;
hour.Dump();

Prints Ora01 .

If you want the hour part after Ora you'd have to group the digits :

var pattern = @"Ora(?<hour>[0-9]{2})";

var match = Regex.Match("/19/Ora01", pattern);

var hour = match.Groups["hour"].Value;
Console.WriteLine(hour);

This prints :

01

You don't explain what kind of validation you want to perform, eg whether the slashes matter or not, whether 19 should be there and eg be treated as a year.

If you want to ensure the string follows this format and the first part is two-digit number, you could use eg @"/(?<year>\\d{2})/Ora(?<hour>\\d{2})" :

var pattern = @"/(?<year>\d{2})/Ora(?<hour>\d{2})";

var match = Regex.Match("/19/Ora01", pattern);

var hour = match.Groups["hour"].Value;
var year = match.Groups["year"].Value;
Console.WriteLine($"{year} {hour}");

This prints :

19 01

Only if the format is correct.

Answer 4

In regular expression ^ means match from start of the string.

Just like $ means match to end of the string.

Simply remove ^ from your pattern and your code should work.

Answer 5

Regex is the best way to do this:

string pattern = "\\/(.*?)\\/(.+)";
string text = "/19/Ora01";
Match match = Regex.Match(text, pattern);
string first = match.Groups[1].Value;
string second = match.Groups[2].Value;

Console.WriteLine(first);
Console.WriteLine(second);

Also @Panagiotis Kanavos is probably the best answer and the most complete one.

Answer 6

You could use string.Split for this, too. Might be faster then regex but depends on your needs.

With string.Split this could look like

var result = start.Substring(start.LastIndexOf("/") + 1);

If you want to use regex you have to remove the "^". For easy testing and more information have a look at regexr.com