如何使用正则表达式保留分隔符

Question

如何使用正则表达式保留分隔符？

我尝试了以下

string str = "user1;user2;user3;user4";

            Regex regex = new Regex(@"\w;");    

            string[] splites = regex.Split(str);
            foreach (string match in splites)
            {
                Console.WriteLine("'{0}'", match);
                Console.WriteLine(Environment.NewLine);
            }

输出：

user1
user2
user3
user4

我想如下但不要：

输出：

user1;
user2;
user3;
user4

Answer 1

Regex.Matches似乎更合适：

string str = "user1;user2;user3;user4";
Regex re = new Regex(@"\w+;?");
foreach (var match in re.Matches(str)) {
    Console.WriteLine(match);
}

Demo run

---

或者你可以使用lookbehind断言：

string str = "user1;user2;user3;user4";
Regex re = new Regex(@"(?<=;)");
foreach (var match in re.Split(str)) {
    Console.WriteLine(match);
}

Demo run

Answer 2

你可以尝试这样的事情

        string str = "user1;user2;user3;user4";
        MatchCollection matchs= Regex.Matches(str, @"[\w]+;?");
        foreach (Match m in matchs)
        {
            Console.WriteLine(m.Value);
        }