C# Where to put general methods?

Question

In my application I have a method to check a variable is a number or not. This method is called more than once in my code. The method is called from the codebehind pages. Like this method I have more methods which i cannot place within a single class (like Staff). Where should I put this kind of methods?

Answer 1

In a utility class file.

Answer 2

I'm assuming your referring to a String variable. If that's the case I would suggest one of two things

1. If you're using PRE .NET 3.0 you could put it in a StringHelper class like so:

   public static class StringHelper
   {
     public static bool StringIsNumber(String value)
     {
       //do your test here
     }
   }
   

2. If you're using POST .NET 3.0 you could refactor them as extension methods and do something like this

   public static class StringExtensions
   {
       public bool IsNumber(this String value)
       {
       //do your test here
       }
   }
   

Answer 3

Sounds like you might be able to use the built-in functions int.TryParse(string, out int) or double.TryParse(string, out double) which both return a bool, but in any case go for ck's suggestion.

Answer 4

In C# 3.0, I would probably make this an extension method on the string class. I would group all of my string extensions into a single static class to improve readability.

 public static class StringExtensions
 {
      public static bool IsNumeric( this string source )
      {
          if (string.IsNullOrEmpty( source ))
          { 
               return false;
          }
          ...
      }

      public static bool IsMoney( this string source )
      {
          ...
      }

      ...
 }

Usage:

 if (amountLabel.Text.IsNumeric())
 {
    ...
 }