I want to find out, whether my string contains a text like #1, #a, #abc, #123, #abc123dsds and so on... ('#' character with one or more characters (digits and letters).
My code so far won't work:
string test = "#123";
boolean matches = test.Contains("#.+");
The matches variable is false.
String.Contains does not accept a regex.
Use Regex.IsMatch:
var matches = Regex.IsMatch(test, "#.+");
@"#[\p{L}\d]+" pattern.test.Contains("#.+"); does not "understand" regular expressions. It literally checks if the string test literally contains #.+ sequence of characters, which #123 does not contain.
Use Regex.IsMatch instead:
bool matches = Regex.IsMatch(test, "#.+");
You need to use Regex in order to use a regex pattern.
string text = "#123";
Regex rgx = new Regex("#[a-zA-Z0-9]+");
var match = rgx.Match(text);
bool matche = match.Success)
Or without regex, you can use a combination of StartsWith, Enumerable.Any and char.IsLetterOrDigit methods like;
var s = "#abc123dsds+";
var matches = s.Length > 1 && s.StartsWith("#") && s.Substring(1).All(char.IsLetterOrDigit);
s.StartsWith("#") && s.Substring(1).All(Char.IsLetterOrDigit)? However, currently it also accepts # as valid.
## or ### are does not match in my answer.# is not a letter of course. I delete that sentences. My answer is better. HAHA :)"#" as match even if # should be followed by a letter or digit. So a Length > 1 is required. It's subjective but imo string methods are simpler.?: solve this. Updated.Well this worked for me. \# checks if it starts with #, \w checks if it is a word.
class Program
{
static void Main(string[] args)
{
string text = "#2";
string pat = @"\#(\w+)";
Regex r = new Regex(pat);
Match m = r.Match(text);
Console.WriteLine(m.Success);
Console.ReadKey();
}
}
String.Containsdoes not accept a regex. UseRegex.IsMatch(test, "#.+").booleaninstead ofbool?[A-Za-z0-9]instead of., because as is you could simply use.startsWith("#")and.length > 1.