Object Creation in C#: Step-by-Step Guide
Tags: csharp, dotnet, programming, tutorial
Published: 2024-03-01 12:00:00

Behold, fellow coders, I present to you a comprehensive treatise on Object Creation in C#! Can you feel the excitement? Buckle up, because we’re about to dive deep into the C# universe, exploring how to create objects, unleash the power of JSON/XML, tinker with dynamic and anonymous objects, and even touch on mock objects for testing. You ask, why should you listen to me? Well, let’s just say I’ve been around the C# block a time or two.

## Introduction to Object Creation in C# #

Taking our first baby steps into the vast cosmos of C#, let’s discuss object creation. Shocker, eh? In the sections that follow, we’ll be exploring different aspects of object creation, spinning up some examples and having a grand time!

```csharp
class Program
{
   static void Main()
    {
        Person obj = new Person(); // Here is your first object creation
        obj.DisplayInfo(); // Calling DisplayInfo() method of Person Class
    }
}
```

In the example above you see a basic object being created in C#. `Person obj = new Person();`? It’s as simple as that! But seriously folks, there is much more to it. Dive down further and we’ll break it all apart for you.

## Pillars of Object-Oriented Programming in C# #

Object-oriented programming (OOP), I’m sure you’ve heard of it. Like a three-legged stool, it stands on three pillars: Encapsulation, Inheritance, and Polymorphism. Sound like something out of a sci-fi movie? Well, in a way, it kinda is, because it’ll transform your mundane block of code into an efficient powerhouse. Let’s decode it.

### Encapsulation in C# #

Encapsulation, sounds like some techno-core band, right? But it’s the principle that binds together the data (fields) and functions that manipulate the data, into a single unit, which we call an `Object`. Still, music to your ears?

```csharp
public class BankAccount
{
    private double balance = 0;
    public void Deposit(double amount){ balance += amount;}
    public double ShowBalance(){ return balance;}
}
```

Here `balance` is the data that we are encapsulating and `Deposit()` and `ShowBalance()` are the methods that manipulate this data. Isn’t encapsulation absolutely riveting?

### Inheritance in C# #

The fancy thing with inheritance is that you can have one class (`derived`) acquire the properties and methods of another class (`base`). It’s like you getting your grandparent’s cheekbones, only cooler!

```csharp
public class Vehicle
{  
    public string brand = "Ford";  
    public void honk() 
    {  
        Console.WriteLine("Tuut, tuut!");  
    }  
}  

public class Car : Vehicle
{  
    public string modelName = "Mustang";  
}  
```

`Vehicle` class is the base class and `Car` is the derived class which inherits from the `Vehicle` class. So, how about a ride in our Mustang?

### Polymorphism in C# #

This might sound like a creature from Greek mythology, but it’s C#’s way of allowing a single entity, such as a method or an object, to take on many forms. Like an actor playing multiple roles. Watch the magic happen…

```csharp
public class Bird
{
    public virtual void Fly()
    {
        Console.WriteLine("This bird can fly.");
    }
}

public class Penguin : Bird
{
    public override void Fly()
    {
        Console.WriteLine("This bird can't fly."); // A penguin can't fly so we override the Fly method
    }
}
```

Here, the `Fly()` function exhibits polymorphism. Depending on the type of bird, it takes on different behaviours.

## C# Object Creation

Now you got the basics covered and are all warmed up, let’s venture into the entrancing world of C# object creation and see what we can cook up from the fundamentals to the advanced stuff. Ready, set, go!

### Constructing Objects in C# – Basic Overview

Objects in C# are like clay in the hands of a potter. You can shape and mold them into whatever you need. But you might wonder, how do we get the clay in the first place? Let’s create some using `new` keyword…

#### C# Create Json Object

Creating JSON objects in C#? Easier than making a PB&J! All you need is the Newtonsoft.Json library and a few lines of code. Feast your eyes on this:

```csharp
var details = new{ Name = "John Doe", Age = 27 };
string jsonString = JsonConvert.SerializeObject(details); // This will create a Json object
```

We’re creating an anonymous object named `details` and then converting it to JSON string with `JsonConvert.SerializeObject(details)`. Voila! A JSON string!

#### C# Create Dynamic Object

Let’s talk about dynamic objects, these little creatures of C# that allow you to add and remove properties and methods at runtime. How cool is that, huh? Brace yourself:

```csharp
dynamic person = new ExpandoObject();
person.Name = "John Doe";
person.Age = 27;
```

`ExpandoObject` allows creating a dynamic object and adding properties on the fly. Endless possibilities. Makes you feel like a magician, doesn’t it?

### Constructing Arrays of Objects in C# #

Creating [arrays](https://www.bytehide.com/blog/array-csharp) of objects? It’s like creating an infantry to charge forward. You’ve got more power at your disposal. Ready to command your infantry? Engage!

#### Create Array of Objects C# #

Creating an array of objects in C#, it’s like creating a line-up of your favorite superhero team. Here’s how to assemble your Avengers:

```csharp
Person[] personArray = new Person[3];
personArray[0] = new Person { Name = "Harry", Age = 23 };
personArray[1] = new Person { Name = "Ron", Age = 24 };
personArray[2] = new Person { Name = "Hermione", Age = 23};
```

You’ve just created an array of `Person` objects, initialized it with three badass wizards. Always remember “You’re a developer, Harry”!

## Working with JSON and XML in C# #

We’ve conquered object creation and arrays, now let’s explore the vast wilderness of JSON and XML. Frightening? Nah! It’s like choosing between pancakes and waffles. Both yummy, just different use cases.

### Understanding Json in C# #

JSON, or JavaScript Object Notation for the uninitiated. It’s taking over the world by storm. In the context of C#, it provides a convenient way to store and exchange data. Ever wondered how to create JSON from objects in C#? Hold my beer…

#### Create Json from Object C# #

```csharp
Person person = new Person { Name = "Harry Potter", Age = 20 };
string jsonString = JsonConvert.SerializeObject(person);
```

Now we’ve converted our `Person` object to JSON string ready to be consumed by various applications; as easy as _Accio JSON_!

### Understanding XML in C# #

Didn’t quite take to JSON? No problem, we’ve got XML waiting in the wings. It’s another popular choice for storing and transporting data. It’s old school, but classic is always classy, right?

#### C# Create XML from Object

```csharp
Person person = new Person { Name = "Harry Potter", Age = 20 };
XmlSerializer xs = new XmlSerializer(typeof(Person));
using (StringWriter sw = new StringWriter())
{
    xs.Serialize(sw, person);
    string xmlString = sw.ToString();
}
```

We serialize our person object into XML string using `XmlSerializer`. It’s not magic, but it’s pretty close!

## Understanding Dynamic and Anonymous Objects in C# #

Dynamic and anonymous objects in C#, they’re like Clark Kent and Superman. The same but different! Let’s unmask them.

### Dynamically Create Object C# #

Creating dynamic objects in C#, it’s a jungle out there. But as the creator, you’ve got the power to add properties and methods on the fly. Here’s how:

```csharp
dynamic dynamicPerson = new ExpandoObject();
dynamicPerson.FirstName = "John";
dynamicPerson.LastName = "Doe";
```

There you go! You can now add any properties you want in that dynamic object, faster than Clark Kent changing into Superman!

### C# Create Anonymous Object

Anonymous objects, fascinating creatures aren’t they? They’re like ninjas, unassuming but powerful. See them in [action](https://www.bytehide.com/blog/action-in-csharp-tutorial):

```csharp
var anonymousPerson = new { FirstName = "John", LastName = "Doe" };
```

Quicker than a flick of a wand, isn’t it? And just like that, you’ve got an anonymous object in your hands!

## Testing Objects in C# #

Why do we test? The answer seems quite straightforward – to ensure our code runs smoothly, catches all unexpected behavior, and generally does what it is supposed to do. In the software development process, testing code is as essential as writing the code itself.

In C#, one such testing method involves the use of mock objects. A mock object is a fake object in the system that decides whether the [unit test](https://www.bytehide.com/blog/unit-testing-csharp) has passed or failed. It has expectations about calls that it is going to receive, and it can throw an [exception](https://www.bytehide.com/blog/5-good-practices-for-error-handling-in-c) if it receives a call it doesn’t expect during testing.

A mock object can also return a specific value when called in a certain way. In a nutshell, mock objects are a powerful tool that can — to quote Spiderman — help you do whatever a unit test can!

### C# Create Mock Object

Creating mock objects in C# has become a lot easier with the Moq library. The Moq library uses a very intuitive, fluent, and strongly-typed .NET API, which makes it easier to mock objects.

Here’s a simple example of creating a mock object for an imaginary IOrder interface:

```csharp
// Create a new mock object
Mock <IOrder> mockOrder = new Mock <IOrder>();

// Set up the mock object to return a specific value
mockOrder.Setup(x =>; x.Submit()).Returns(true);

// The mockOrder object will now always return true when Submit is called
```

In the above code, `mockOrder` is a mock object based on the IOrder interface. It has been set up to always return `true` when its `Submit` method is called.

Moq also allows us to verify that certain actions were performed on our mock objects during the execution of our code. Consider the following example:

```csharp
// Assume we have a OrderProcessor class which processes our orders
OrderProcessor processor = new OrderProcessor();

// We pass our mock object to the processor
processor.ProcessOrder(mockOrder.Object);

// We then verify that the Submit method was called on our mock object
mockOrder.Verify(x =>; x.Submit(), Times.Once);
```

Here we verify that `Submit` was indeed called on our mock object exactly once when `ProcessOrder` was called in our `OrderProcessor`. If this is not fulfilled, Moq will throw an exception.

Using mock objects is an ingenious way of testing objects in isolation, without setting up their dependencies. Understanding the ins and outs of testing, including the use of mock objects, is paramount. This way, you gain the magical ability to guard your code against unexpected behaviors and bugs.

In C# coding and testing go hand in hand, and knowing how to test your objects, safely and efficiently, is a real power-up for your developer toolset. The power to debug, change, and improve is right there in your fingertips, quite literally. Go forth and test uncharted territories of your code. And always remember – with great code, comes great debugging responsibility. You now have the wisdom, will you use it to venture deeper into the art of testing in C#? Your journey into becoming a true C# master continues.