C＃查找带有模式的大字符串中的所有子字符串

Question

Consider I have the following string:

jkasdlue as 12&sdaj__3982[source=saj_/29]sj*2&7^;'asj[source=-js/.2]_jsld+=[source=283]

I'd like to get output of array of string below:

{"saj_/29","-js/.2","283"}

Any help would be appreciated. Thanks.

UPDATE

Okay. Pardon me if my question is too broad or seems no effort from me. I need to refine the pattern which should accept only alphanumeric characters, "-", "_", ".", "/", ":", " ". Follow someone suggestion below to use regex.

For now this regex seems to work:

\[source=[A-Za-z0-9-_ \\\/.:]+\]

Next step substring each match to eliminate the open tag "[source=" and the close tag "]"

Any better idea to reduce the process?

Answer 1

You just need \\[source=([A-Za-z0-9-_ \\\\/.:]+)\\] (if you do not need to match a backslash. remove \\\\ ) and access the value without last ] and initial [source= using match.Groups[1].Value .

var res = Regex.Matches(str, @"\[source=([A-Za-z0-9-_ \\/.:]+)\]").Cast<Match>().Select(match => match.Groups[1].Value).ToList();

See C# demo :

var str  = "jkasdlue as 12&sdaj__3982[source=saj_/29]sj*2&7^;'asj[source=-js/.2]_jsld+=[source=283]";
var res = Regex.Matches(str, @"\[source=([A-Za-z0-9-_ \\/.:]+)\]").Cast<Match>().Select(match => match.Groups[1].Value).ToList();
Console.WriteLine(String.Join("\n", res));

Result:

saj_/29
-js/.2
283

Note that it is also possible to get the results using look-arounds, but as they are "expensive", less efficient and just not necessary here, I would not advise to use it. Here is link to a regex demo :

(?<=\[source=)[A-Za-z0-9-_ \\/.:]+(?=\])
^^^lookbehind^                    ^^^^^^ - lookahead          

And in C#:

var res = Regex.Matches(str, @"(?<=\[source=)[A-Za-z0-9-_ \\/.:]+(?=\])").Cast<Match>().Select(match => match.Value).ToList();