regex matches with intersection in C#

Question

I wonder if it is possible to get MatchCollection with all matches even if there's intersection among them.

string input = "a a a";
Regex regex = new Regex("a a");
MatchCollection matches = regex.Matches(input);
Console.WriteLine(matches.Count);

This code returns 1, but I want it to return 2. How to achive it?
Thank you for your help.

Answer 1

string input = "a a a";
Regex regexObj = new Regex("a a");
Match matchObj = regexObj.Match(input);
while (matchObj.Success) {
    matchObj = regexObj.Match(input, matchObj.Index + 1); 
}

will iterate over the string starting the next iteration one character after the position of the previous match, therefore finding all matches.

Answer 2

您可以在while循环中将“aa”替换为“a”并将其与正则表达式再次匹配，直到没有匹配为止。