正则表达式基础 之 ?

Console.WriteLine (Regex.Match ("color", @"colou?r").Success); // True
Console.WriteLine (Regex.Match ("colour", @"colou?r").Success); // True
Console.WriteLine (Regex.Match ("colouur", @"colou?r").Success); // False

Match m = Regex.Match ("any colour you like", @"colou?r");
Console.WriteLine (m.Success); // True
Console.WriteLine (m.Index); // 4
Console.WriteLine (m.Length); // 6
Console.WriteLine (m.Value); // colour
Console.WriteLine (m.ToString()); // colour

Match m1 = Regex.Match ("One color? There are two colours in my head!",@"colou?rs?");
Match m2 = m1.NextMatch();
Console.WriteLine (m1); // color
Console.WriteLine (m2); // colours

foreach (Match m in Regex.Matches("One color? There are two colours in my head!", @"colou?rs?"))
Console.WriteLine (m);