Convenient Uses of C# Extension Methods - Part 2

In this article I'll discuss another way I've made my life easier with C# extension methods. In A Convenient Use of C# Extension Methods - Part 1", I showed how an extension method can be used to conveniently display a user-friendly version of an enumerated type.

Over the years, I've built up a number of libraries that I tend to use in any project I work with. In one such library, I have a couple of extension methods for strings to make my code easier to read and maintain.

When it comes to strings, I hate checking for null or empty / whitespace this way:

var inputValidator = new InputValidator();
var userComment = GetUserComment();
var sanitizedComment = inputValidator.SanitizeComment(userComment);
if (string.IsNullOrEmpty(sanitizedComment) == false)
{
    // do something with this valid comment....
}

When I see code like the highlighted line above, I have to think for a few seconds to make sure I know what the conditional is really checking. This slows me down when scanning or debugging code.

So, I have a couple of extension methods that make the code more readable.

public static class StringExtensions
{
    public static bool HasValue(this string source)
    {
        return (!source.IsEmpty());
    }
    public static bool IsEmpty(this string source)
    {
        return (string.IsNullOrWhiteSpace(source));
    }
}

With these extensions in scope, we can now do this:

if (sanitizedComment.HasValue())
{
    // do something with this comment....
}

A similar case exists when trying to Trim() a string or get its Length(). These methods will fail if the strings are null. With a few extension methods, we can automatically handle the null when we call the methods:

public static class StringExtensions
{
    public static string SafeTrim(this string source)
    {
        return (source == null) ? "" : source.Trim());
    }

    public static int SafeLength(this string source)
    {
        return (source == null) ? 0 : source.Length;
    }
}

With those extension methods in scope, we can write code like this:

if (newComment.SafeLength() > MaxExcerptLength)
{
    // do something with comment
}
var trimmedComment = newComment.SafeTrim();

As you can see, with a very little amount of work, the code is cleaner and more readable.