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C# 6 Features – Nameof Expressions

Name BadgeIn the latest post on my series about C# 6’s features, I want to look at nameof expressions. There are times when you need the string value of variables or methods or classes in your code. That could be to return an argument exception, it could be to have some sort of property changed notification, or it could even be to get the string value of an enumeration value.

Previously, you had to either have “magic strings” in your application or any number of tricks to abstract away what are basically the magic strings. If you changed the name of a variable, parameter, method, class, or enum, nothing would ensure that you went back and updated your “magic strings”. Perhaps if you had written very finely-grained unit tests (and you remembered to update those when you changed a variable name), you might get a warning, but that is a tremendous amount of discipline. That’s where C# 6 is here to save our bacon.

As an example, here is something we might have done previously

You can see how I could change the parameter name from foo to something else and the compiler won’t care if I fix the call to ArgumentNullException() or not. However, nameof fixes and prevents that.

The benefit here is that if I change the parameter and forget to change nameof(foo) like this:

You actually will get a compile time error that says “The name ‘foo’ does not exist in the current context”. Some people hate using the compiler as a unit test, but I don’t. It is basically “round one” of testing. I think the issue arises when it is the the only means of testing used, but it is just another tool in the toolbox that we should use.

As I mentioned earlier, you can use it to get the names of classes, methods, and it lets you stop the SomeEnum.SomeValue.ToString() madness. It is the same syntax and would look like this

As I said at the beginning of this series, much of C# 6’s features aren’t mind-blowing, but instead are small improvements to help smooth out some edges. Are you using nameof? Are you going to when you get the chance?

Podcast Episode 46 – Disrupted

Disrupted BookI recently finished reading a book by Dan Lyons called Disrupted: My Misadventure in the Start-Up Bubble on the recommendation of my friend Dustin Rogers. This book is an inside look at a company called HubSpot that – according to Lyons – exhibits some of the worst and most stereotypical traits of Silicon Valley companies. In this episode, I review the book and talk about some of the things that drive me nuts about these kinds of companies.


Links Mentioned in this Show:
Disrupted on Amazon
Dustin’s Podcast Episode
HubSpot’s Rebuttal to the Book
HyperDev Announcement
HyperDev Site

You can also subscribe to the podcast at any of these places:
iTunes Link RSS Feed Listen on Stitcher
In addition, my podcast is available on DoubleTwist and the Windows Marketplace.
Thanks to all the people who listen, and a special thanks to those who have rated me. I really appreciate it.
Listen here:

C# 6 Features – Using Static

StaticFor this next post in my series on the new features in C# 6, I’m going to cover the using static syntax. This feature is also 100% syntactic sugar, but it can be helpful. Unfortunately, it also comes with quite a few gotchas.

I’m sure all of us are familiar with writing code like you see below. The WriteLine() method is a static method on the static class Console.

Because Console is a static class, we can treat it as a “given” and just now include it in our using statements. Console.WriteLine() is actually System.Console.WriteLine() if we include the namespace. However, since we are including “using System;” at the top of the file, we don’t have to type it out. This is the exact same concept.

Now instead of just “using”, I’ve included “using static” and included the full name of the static class, in this case System.Console. Once that is done, I’m free to just call the WriteLine() method as if it were locally scoped inside my class. This is all just really syntatic sugar. When I use Telerik’s JustDecompile to analyze the program and give me back the source, this is what I get.

If we dig even further into the IL, you can see that it agrees that we are still just making a call to WriteLine() inside of the System.Console class.

Okay, that makes sense. Seems potentially helpful. Where do these promised “gotchas” come in? Our issues start to arise when you have multiple “using static” declarations in a file. If those static classes have methods inside them with the same name, conflicts can happen. Let’s take a look at one place where this can absolutely happen in a commonly used area of .Net.

In this simple contrived example, I’m iterating through all of the files in a directory and if they don’t exist in a backup location, I copy them there. This doesn’t deal with versioning, etc, but it does give us some basic System.IO examples to work with. Now, if I try to simplify the code like this, I get an issue.

This won’t even build. Can you guess why? If you are very familiar with System.IO classes, you might have noticed that there is a System.IO.File.Exists() and a System.IO.Directory.Exists(). Our build error lets us know by saying, “The call is ambiguous between the following methods or properties: ‘Directory.Exists(string)’ and ‘File.Exists(string)'”. One way to get around this is to just be explicit at the ambiguous part like this:

I don’t know how that makes me feel. It seems like at least a small code smell. Maybe in these occasions, you don’t use this shortcut if it feels wrong. In general, I could see this being like the Great Var Debate of 2008™. People thought that var foo = new Bar(); was smelly compared to Bar foo = new Bar();, but it seems like most people have moved past it. Maybe I’m just on the beginning of this wave of change and I’ll stop yelling for the kids to get off of my lawn soon. At the moment, however, I’m probably going to file using static in the “not something I’m going to really use” pile.

Podcast Episode 45 – Erik Dietrich on The Expert Beginner

In today’s episode, I interview Erik Dietrich from Daedtech.com. Erik wrote a blog series about something he called “The Expert Beginner”. When I read that, I felt kind of convicted because I was worried that I was wreaking havoc all of the city with “Expert Beginnerdom”. Listen in to find out what an Expert Beginner is and if you are one or know one!


Links Mentioned in this Show:
Erik’s Blog
Erik on Twitter
The Post that Started it All
Erik’s Books and Pluralsight Courses
Pick of the Week: SwiftNinja.io

You can also subscribe to the podcast at any of these places:
iTunes Link RSS Feed Listen on Stitcher
In addition, my podcast is available on DoubleTwist and the Windows Marketplace.
Thanks to all the people who listen, and a special thanks to those who have rated me. I really appreciate it.
Listen here:

C# 6 Features – String Interpolation

For this post in my series, I want to look at one of my favorite little time savers, String Interpolation. String Interpolation is basically when you put tokens into a string and those are replaced for you by the language. Previously, in C#, we might do one of the following things:

Sometimes, with a long string with a lot of tokens, this can get kind of unwieldy. And, if you reuse tokens (say, a line break, or the person’s name), it can be almost impossible to keep things straight. Other languages have had features like this for awhile.

Swift:

Ruby:

Now, in C# 6, we get that kind of clarity as well. The syntax calls for you to use a dollar sign ($) in front of the string and then use curly braces surrounding the variable reference in the string. Here is an example

New C# 6 String Interpolation:

In my opinion, that beats the pants off of string.Format(). Additionally, you can also reference class properties by the same syntax. Here is another example:

You can also express values from methods:

So, there you go. I can promise you that I’m going to use this instead of string.Format() in every project that is running the necessary framework versions.

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