As a developer, you have probably heard about many programming languages, including C#, Java, C++, C, PHP, and Ruby. In all of them, you can use various data structures, as well as implement algorithms, to solve both basic and complex problems. However, each language has a specificity that’s visible while implementing data structures and accompanying algorithms. As mentioned previously, this book only focuses on the C# programming language. This is also the main topic of this section.

The C# language, pronounced C sharp, is a modern, general-purpose, strongly typed, and object-oriented programming language that can be used while developing a wide range of applications, such as web, mobile, desktop, distributed, and embedded solutions, as well as even games! It cooperates with various additional technologies and platforms, including ASP.NET Core, XAML, and Unity. Therefore, when you learn the C# language, as well as get to know more about data...

To keep things simple, while reading this book, you will create many console-based applications, but the data structures and algorithms could be used in other kinds of solutions as well. The console-based applications will be created in Microsoft Visual Studio 2022 Community. This integrated development environment (IDE) is a comprehensive solution for developing various kinds of projects and is equipped with many great features that simplify the development and testing of your applications.

Just after launching the IDE, we can proceed by creating a new project. To create one, follow these steps:

1. Click on File | New | Project in the main menu.
2. Choose Console App on the right in the Create a new project window.
3. Type the name of the project (Project name), select a location for the files (Location), and enter the name of the solution (Solution name). Then, press Next.
4. In the Additional information window, set the framework version...

While developing applications in the C# language, you could use various data types, which are divided into two main groups, namely value types and reference types. The difference between them is quite simple – a variable of a value type directly contains data, while a variable of a reference type just stores a reference to data, which is located somewhere else.

Here’s an illustration of this:

Figure 1.1 – The difference between value and reference types

As you can see, a variable of a value type (shown as A) stores its actual value directly in the stack memory, while a variable of a reference type only stores a reference here. The actual value is located in the heap memory. Therefore, it is possible to have two or more variables of a reference type that reference the same value, as indicated by the C and D boxes in the preceding figure.

Be careful – it is a simplification!

Please remember that...

To give you a better understanding of data types, let’s start by analyzing the first group, namely value types. They are further divided into the following categories:

• Structs encapsulating data and functionalities, which are divided into the following categories:
  • Built-in value types, also referred to as simple types. These are divided into:
    • Integral numeric types
    • Floating-point numeric types
    • Boolean values
    • Unicode UTF-16 characters
  • Value tuples
  • User-defined struct types
• Constants
• Enumerations

All of these groups will be described in this section, starting with the simple types.

Integral numbers

The first group of built-in value types are the integral numeric types, which allow you to store various integer values. Similar to other simple types, they can be used either as keywords or as types from the System namespace. Such types differ by the number of bytes used and whether signed or unsigned integral values are represented by them.

Imagine...

The second main group of types is reference types. As a quick reminder, a variable of a reference type does not directly contain data because it just stores a reference to data, which is located somewhere else. In this group, you can find four built-in types, namely object, string, delegate, and dynamic. Moreover, you can declare classes, records, and interfaces. Nullable reference types exist as well. All of these types will be described in this section. Let’s get started!

Objects

The Object class (the object alias) is declared in the System namespace and performs an important role while developing applications in C#. Why? Because all other types in the unified type system of C# inherit directly or indirectly from Object. This means that built-in value types, built-in reference types, as well as user-defined value types and user-defined reference types, are derived from the Object class.

Imagine an object

If you want to understand the object type...

This was only the first chapter of this book, but it contained quite a lot of information that will be useful while you’re reading the remaining ones. First, the C# programming language was briefly presented with a focus on showing various data types, both value and reference ones. You learned the difference between them and why understanding this difference is so important while developing applications.

Next, you saw various value types, including the built-in ones, such as integral numeric types, floating-point numeric types, Boolean type, and Unicode characters. Then, you learned about constants, enumerations, value tuples, user-defined struct types, and nullable value types. All of these were equipped with detailed descriptions, as well as some code examples to make understanding easier and faster.

Finally, you learned about the second group of types, namely reference types. Here, you saw the object and string types, classes, records, interfaces, as well as...