how get integer only and remove all string in C# [duplicate]

Answer 1

You should use Regular Expressions -- they're a pretty powerful way to match strings of text against certain patterns, and this is a great scenario in which to use them.

The pattern "\d+" will match a sequence of 1 or more digits. A simple method that uses this pattern to extract all numbers from a string is as follows:

public static List ExtractInts(string input)
{
   return Regex.Matches(input, @"\d+")
      .Cast()
      .Select(x => Convert.ToInt32(x.Value))
      .ToList();
}

So you could use it like this:

List result = ExtractInts("( 01 - ABCDEFG )");

For some more detailed info on Regular Expressions, see this page (MSDN) or this page (helpful "cheat sheet").