Where should I put miscellaneous functions in a .NET project?

Question

I found myself having to remove the first line of a string quite often while working on a text parser in C#. I put together a simple function to do that for me, but coming from a PHP background, I have no idea where to put it since I can't define a function outside a class. What's a customary way of doing that in .NET? Do I create a static class to store my function?

Answer 1

I generally make a Helper or Utility static class and then put corresponding helper functions in there.

Additionally, I try to keep the Helper and Utility classes grouped logically - putting the text parsing functions alongside the object conversion functions is nonsensical. The confusion is cleared up with a TextUtils class and a ConversionUtils class.

Answer 2

Usually I create a Utilities class and define static helper methods.

Answer 3

I don't think there's a standard for this. I tend to make a static class called BlahUtil. For your example, I'd make it a static method on StringUtil. This helps me group related methods into sensible units, making it easier to discover them and share them across teams.

You can also then choose which of these methods are exposed as extension methods (since c# 3.0):

public static class StringUtil
{
    public static string RemoveFirstLine(this string multiLineString)
    {
        // ...
    }
}

Answer 4

Yes, static helper classes are usually the way to do this.

Also, in C# 3 you can declare the method like this:

public static string RemoveFirstLine(this string s) {
    ...
}

to make it an extension method. Then you can call it on any string as if the method was declared on the string type itself.

Answer 5

I'd create a static worker class for such functions. Maybe not the nicest way, but the one which keeps things simple... ;)

K

Answer 6

Use an extension method for a string. That's what they are for.

Answer 7

I've done the static "helper" classes but after some analysis; this type of helper function always ends up as a distinct class implementation. In your case you'd have a "basic text parser" class and a derived class that overrides the "parse" method.

Answer 8

You can use a class with static methods. Something like ParserUtils.RemoveFirstLine(). On .NET 3.5 and above you can sometimes use extension methods when your utility functions are related to a class you cannot modify, like the String class. Intellisense will show the extension method on any string object in the project.

Answer 9

Be careful!

• Generic utility functions which are cross cutting should live in a higher utility namespace. String parsing, File manipulation, etc.

• Extension objects should live in their own namespace.

• Utility functions that apply to a specify set of business objects or methods should live within the namespace of those objects. Often with a Helper suffix, ie BusinessObjectHelper. Naming is important here. Are you creating a container for miscellaneous methods, or would it make more sense to group them into specialized objects, ie a parser?

Answer 10

If you are using C# 3.0, you might want to consider using an extension method!

public static class StringExtensions
{
    public static string RemoveFirstLine(this string myString)
    {
         return myString.Remove("line..!");
    }
}

Then in code you can do this:

string myString = "Hello World etc";

string removedLineString = myString.RemoveFirstLine();

Answer 11

Extensions are the way to go in those case. It literally add your function to the occurence. Only thing is that it's not possible to do static method in 2008.