Reactive Programming and Procedural Programming are fundamentally distinct paradigms, each suited for particular development contexts.

Core Principles

• Reactive Programming focuses on reactive data composition, employing data flows and change propagation.

  • Example: UI event handling, streaming, real-time applications.

• Procedural Programming emphasizes sequential task execution through explicit actions and control flows.

  • Example: User input processing, algorithms.

Key Components and Concepts

Reactive Programming

• Data Stream: An ongoing sequence of data that allows concurrent data handling.
• Observer: Any entity that subscribes to a stream and reacts to the data.
• Subscriber: A reader that is attached to a data stream.

Procedural Programming

• Variables: These are storage units for data values and have a single, non-concurrent phase.

Reactive Programming represents an ongoing data flow with a stream that can be subscribed to by multiple observers. On the other hand, Procedural Programming presents data as a single value stored in a variable, which gets executed, taking actions as inputs and producing outputs.

Code Example: Reactive Programming

Here is the C# code:

using System;

public class Program
{
    public static void Main()
    {
        var numbers = new int[] { 1, 2, 3, 4, 5 };

        IObservable<int> numberObservable = numbers.ToObservable();

        using (numberObservable.Subscribe(Console.WriteLine))
        {
            Console.WriteLine("Press any key to exit.");
            Console.ReadKey();
        }
    }
}