Turning string.Format into an Extension Method

string.Format is the Bread and Butter function of every .Net developer, but somehow it feels a bit verbose. Here is a little extension method that allows you to do this:

string myTestString = "Hello {0}, Welcome to {1}, have a nice {2}!"; // Imagine this comes from a database or localized resource
string uname = "Dave";
string facility = "Initrode";
string timeOfDay = "afternoon";

// "old" way
lblWelcome.Text = string.Format(myTestString, uname, facility, timeOfDay);

// "new" way
lblWelcome.Text = myTestString.FormatString(uname, facility, timeOfDay);

// It gracefully handles nulls as long as it's a string, it will return string.Empty on a null string
string myNullString = null;
lblWelcome.Text = myNullString.FormatString(uname, facility, timeOfDay);

// Buzzword of 2009: Fluent Interface!
lblWelcome.Text = myTestString.Replace("Hello","Howdy").FormatString(uname,facility,timeOfDay).Trim().Reverse();

Not really life changing, but it's one of those small things that just "feel" nicer/more fluent. Thanks to Kevin Dente for reminding me of string.Format again. I am using it every day and I always had it in the back of my head that I find it a bit "clunky". So here is the extension method:

    public static class StringExtensionMethods
        public static string FormatString(this String input, params object[] args)
            if (input == null) return string.Empty;
            return string.Format(input, args);

Not Rocket Science, I know, but as said, even small things count if you just encounter them often enough 🙂

Comments (1)

jwcJanuary 8th, 2010 at 19:10

Thanks, I feel the same way about string.Format. Most of the time I find that I want to format a string and then I have to go back and add parens around it and so on. Feels like too much work. This seems so much simpler.