using System;

using System.Collections.Generic;

using System.Text.RegularExpressions;

​

List<string> inputs = new()

{

    "Hello, World!",

    "Something something Hello!",

    "  Hello",

    "Hello from Dev Leader!",

};

​

string pattern = "^Hello";

Regex regex = new Regex(pattern);

​

foreach (var input in inputs)

{

    Match match = regex.Match(input);

    Console.WriteLine(

        $"'{input}' {(match.Success ? "did" : "did not")} " +

        "match the string starting with the pattern.");

}