Using ExpandoObject to create objects that you can add properties, methods, and events to.
Buy “C# 6.0 Cookbook” in early release.
Editor’s note: This is an excerpt from “C# 6.0 Cookbook,” by Jay Hilyard and Stephen Teilhet. It offers more than 150 code recipes to common and not-so-common problems that C# programmers face every day. In it, you’ll find recipes on asynchronous methods, dynamic objects, enhanced error handling, the Rosyln compiler, and more.
You want to be able to build up an object to work with on the fly at runtime.
ExpandoObject to create an object that you can add properties, methods, and events to and be able to data bind to in a user interface.
We can use
ExpandoObject to create an initial object to hold the
Name and current
Country of a person.
dynamic expando = new ExpandoObject();
expando.Name = "Brian";
expando.Country = "USA";
Once we have added properties directly, we can also add properties to our object in a more dynamic fashion using the
AddProperty method we have provided for you. One example of why you might do this is to add properties to your object from another source of data. We will add the
Start writing shorter and less bug-prone Python code.
It is hard to get a consistent opinion on just what functional programming is, even from functional programmers themselves. A story about elephants and blind men seems apropos here. Usually we can contrast functional programming with “imperative programming” (what you do in languages like C, Pascal, C++, Java, Perl, Awk, TCL, and most others, at least for the most part). Functional programming is not object-oriented programming (OOP), although some languages are both. And it is not Logic Programming (e.g., Prolog).
I would roughly characterize functional programming as having at least several of the following characteristics:
- Functions are first class (objects). That is, everything you can do with “data” can be done with functions themselves (such as passing a function to another function). Moreover, much functional programming utilizes “higher order” functions (in other words, functions that operate on functions that operate on functions).
- Functional languages eschew side effects. This excludes the almost ubiquitous pattern in imperative languages of assigning first one, then another value to the same variable to track the program state.
- In functional programming we focus not on constructing a data collection but rather on describing “what” that data collection consists of. When one simply thinks, “Here’s some data, what do I need to do with it?” rather than the mechanism of constructing the data, more direct reasoning is often possible.
Functional programming often makes for more rapidly developed, shorter, and less bug-prone code. Moreover, high theorists of computer science, logic, and math find it a lot easier to prove formal properties of functional languages and programs than of imperative languages and programs.
The principles of reactive applications facilitate adaptation.
One of the fascinating things found in nature is the ability of a species to adapt to its changing environment. The canonical example of this is Britain’s Peppered Moth. When newly industrialized Great Britain became polluted in the nineteenth century, slow-growing, light-colored lichens that covered trees died and resulted in a blackening of the trees bark. The impact of this was quite profound: lightly-colored peppered moths, which historically had been well camouflaged and the majority, now found themselves the obvious target of many a hungry bird. Their rare, dark-colored sibling, who had been conspicuous before, now blended into their recently polluted ecosystem. As the birds, changed from eating dark-colored to light-colored moths, the previously common light-colored moth became the minority, and the dynamics of Britain’s moth population changed.
So what do moths have to do with programming? Read more…
Get inspired to create, teach, and learn with the Raspberry Pi.
The Raspberry Pi is a small computer that can be used for a variety of projects, and has been heralded as a great boon to education due to its flexibility and simplicity. While PcPro magazine noted in January of 2014 that Pi’s were “gathering dust” in classrooms, production has not ceased. The usage map is pretty impressive and the Raspberry Pi 2 was recently released.
In February of this year, the Raspberry Pi Foundation announced that they’re starting a mentoring program for people 16-21 years old. Here are four other ways that the Pi is being used in education and growing the tech community.
Improve your odds with the lingua franca of computing.
A boring old C-style language just like millions of developers learned before you, going back to the 1980s and earlier. It’s not flashy, it’s usually not cutting edge, but it is smart. Even if you don’t stick with it, or program in it on a daily basis, having a C-style language in your repertoire is a no-brainer if you want to be taken seriously as a developer.
Microsoft .Net Team Program Manager, Beth Massi, on the open source .NET Core.
You might have heard the news that .NET is open source. In this post I’m going to explain what exactly we open sourced, why we did it, and how you can get involved.
If you’re not familiar with .NET, it’s a managed execution environment that provides a variety of services to its running applications including things like automatic memory management, type safety, native interop, and multiple modern programming languages that make it easier to build all kinds of apps, for nearly any device, quickly. The first version of .NET was initially released in 2002 and quickly picked up steam in many businesses. Today there are over 1.8 billion active installs of the .NET Framework and 6 million .NET developers in the world.
The .NET Framework consists of these major components: the common language runtime (CLR), which is the execution engine that handles running applications; the .NET Framework Base Class Libraries (BCL), which provides a library of tested, reusable code that developers can call from their own applications; and the managed languages and compilers for C#, F#, and Visual Basic. Application models extend the common libraries of the .NET Framework to provide additional libraries that developers can use to build specific types of applications, like web, desktop, mobile device apps, etc. For more information on all the components in .NET 2015 see: Understanding .NET 2015.
There are multiple implementations of .NET, some from Microsoft and others from other companies or open source projects. In this post, I’ll focus on .NET Core from Microsoft.