Get particular parts from a string

Question

I'm trying to get particular parts from a string. I have to get the part which starts after '@' and contains only letters from the Latin alphabet.

I suppose that I have to create a regex pattern, but I don't know how.

string test = "PQ@Alderaa1:30000!A!->20000";
var planet = "Alderaa"; //what I want to get
string test2 = "@Cantonica:3000!D!->4000NM";
var planet2 = "Cantonica";

There are some other parts which I have to get, but I will try to get them myself. (starts after ':' and is an Integer; may be "A" (attack) or "D" (destruction) and must be surrounded by "!" (exclamation mark); starts after "->" and should be an Integer)

Answer 1

You could get the separate parts using capturing groups:

@([a-zA-Z]+)[^:]*:(\d+)!([AD])!->(\d+)

That will match:

• @([a-zA-Z]+) Match @ and capture in group 1 1+ times a-zA-Z
• [^:]*: Match 0+ times not a : using a negated character class, then match a : (If what follows could be only optional digits, you might also match 0+ times a digit [0-9]*)
• (\d+) Capture in group 2 1+ digits
• !([AD])! Match !, capture in group 3 and A or D, then match !
• ->(\d+) Match -> and capture in group 4 1+ digits

Demo | C# Demo

Answer 2

You can use this regex, which uses a positive look behind to ensure the matched text is preceded by @ and one or more alphabets get captured using [a-zA-Z]+ and uses a positive look ahead to ensure it is followed by some optional text, a colon, then one or more digits followed by ! then either A or D then again a !

(?<=@)[a-zA-Z]+(?=[^:]*:\d+![AD]!)

Demo

C# code demo

string test = "PQ@Alderaa1:30000!A!->20000";
Match m1 = Regex.Match(test, @"(?<=@)[a-zA-Z]+(?=[^:]*:\d+![AD]!)");
Console.WriteLine(m1.Groups[0].Value);

test = "@Cantonica:3000!D!";
m1 = Regex.Match(test, @"(?<=@)[a-zA-Z]+(?=[^:]*:\d+![AD]!)");
Console.WriteLine(m1.Groups[0].Value);

Prints,

Alderaa
Cantonica