Creating instances dynamically in C Sharp (C#) - Try It Yourself

Creating instances dynamically

📖 Scenario: Imagine you are building a simple program that creates different types of vehicles based on user input. Each vehicle has a name and a speed. You want to create these vehicle objects dynamically using their class names.

🎯 Goal: Build a C# program that dynamically creates instances of vehicle classes using their names as strings, and then displays their details.

📋 What You'll Learn

Create two classes: Car and Bike, each with a Name and Speed property.

Create a string variable called vehicleType that holds the name of the class to create.

Use Activator.CreateInstance to create an instance of the class named in vehicleType.

Set the Name and Speed properties of the created instance.

Print the Name and Speed of the created vehicle.

💡 Why This Matters

🌍 Real World

Creating instances dynamically is useful when you want to build flexible programs that can create objects based on user input or configuration files without hardcoding all types.

💼 Career

This skill is important for developers working on plugin systems, factories, or any software that needs to load and create objects at runtime based on names or types.

1

Create vehicle classes

Create two classes called Car and Bike. Each class should have two public properties: Name (string) and Speed (int).

C Sharp (C#)

# Your code here

Need a hint?

Use public class ClassName to create classes. Use public string Name { get; set; } to create properties.

2

Set vehicle type variable

Create a string variable called vehicleType and set it to "Car".

C Sharp (C#)

public class Car
{
    public string Name { get; set; }
    public int Speed { get; set; }
}

public class Bike
{
    public string Name { get; set; }
    public int Speed { get; set; }
}

// Create a string variable called vehicleType and set it to "Car"
# Your code here

Need a hint?

Use string vehicleType = "Car"; to create the variable.

3

Create instance dynamically

Use Activator.CreateInstance with Type.GetType(vehicleType) to create an object called vehicle. Then cast it to dynamic. Set vehicle.Name to "Speedster" and vehicle.Speed to 120.

C Sharp (C#)

public class Car
{
    public string Name { get; set; }
    public int Speed { get; set; }
}

public class Bike
{
    public string Name { get; set; }
    public int Speed { get; set; }
}

string vehicleType = "Car";

// Create an instance of the class named in vehicleType using Activator.CreateInstance
// Cast it to dynamic and set Name and Speed properties
# Your code here

Need a hint?

Use Type.GetType(vehicleType) to get the type, then Activator.CreateInstance(type) to create the object. Cast to dynamic to set properties easily.

4

Print vehicle details

Write a Console.WriteLine statement to print the vehicle's Name and Speed in this format: "Vehicle: Speedster, Speed: 120".

C Sharp (C#)

public class Car
{
    public string Name { get; set; }
    public int Speed { get; set; }
}

public class Bike
{
    public string Name { get; set; }
    public int Speed { get; set; }
}

string vehicleType = "Car";

var type = Type.GetType(vehicleType);
if (type == null)
{
    // If type is null, try with namespace
    type = Type.GetType("" + vehicleType);
}
dynamic vehicle = Activator.CreateInstance(type);
vehicle.Name = "Speedster";
vehicle.Speed = 120;

// Print the vehicle details
# Your code here

Need a hint?

Use Console.WriteLine($"Vehicle: {vehicle.Name}, Speed: {vehicle.Speed}") to print the details.