using System;
using System.Data;
using System.Text.RegularExpressions;
class Class1{
static void Main(string[] args){
string IsNotNum = "111west";
string IsNum = " +111 ";
string IsFloat = " 23.11 ";
string IsExp = " +23 e+11 ";
Console.WriteLine(GetNumberFromStr(IsNum)); // +111
Console.WriteLine(GetNumberFromStr(IsNotNum)); //
Console.WriteLine(GetNumberFromStr(IsFloat)); // 23.11
Console.WriteLine(GetNumberFromStr(IsExp)); //
}
public static string GetNumberFromStr(string str)
{
str = str.Trim();
Match m = Regex.Match(str, @"^[\+\-]?\d*\.?[Ee]?[\+\-]?\d*$");
return (m.Value);
}
}