C# Regex: Match Multiple Strings Explained

In C#, you can use the Regex class to match multiple strings. Here is an example code:

using System;
using System.Text.RegularExpressions;

class Program
{
    static void Main()
    {
        string input = "Hello world! This is a test.";
        string[] keywords = { "Hello", "world", "test" };

        foreach (string keyword in keywords)
        {
            // 使用Regex类的静态方法Match来进行匹配
            Match match = Regex.Match(input, keyword);

            if (match.Success)
            {
                Console.WriteLine("Found '{0}' at position {1}.", keyword, match.Index);
            }
            else
            {
                Console.WriteLine("'{0}' not found.", keyword);
            }
        }
    }
}

The output will be:

Found 'Hello' at position 0.
Found 'world' at position 6.
Found 'test' at position 21.

In the example above, we defined a string array called keywords and used a loop along with the Regex.Match method to search for each keyword in the input string. If a match is found, it will output the position of the keyword; otherwise, it will output “not found”.