C# Regex.Match stop match when meet special characters

Question

This is my code:

// Clear strange characters
String string1 = "d34-&%#*%(#**)2121js3412h";
String string2 = Regex.Match(string1, @"\d+").Value;
Console.WriteLine(string2);

The output of above code is: 34 .
The expected output is: 3421213412 .

Why does the Match stop matching at the "-" character (or any special character)?
Did I miss some regex rules?

Answer 1

您可以随时使用Regex.Replace ：

string string2 = Regex.Replace(string1, @"[^0-9]", "");

Answer 2

If you want all matches, use Regex.Matches :

var matches = Regex.Matches(string1, @"\d+").Cast<Match>().Select(x => x.Value);
string string2 = string.Concat(matches);

It has nothing to do with special characters. That is the behaviour of Match method, it returns the first match it found.