Understanding Main() and Runtime Environments — A Developer’s Curiosity

As I was going through my C# code, I remembered a doubt I once had: “Why does the Main function act as the starting point?” 🤔
The answer to this question is mostly known:

• When we run a program, the .NET runtime environment searches for the Main method and starts execution from there.
  🔹 The Main method must be static because the runtime cannot create an object of your class on its own before execution starts.
  🔹 Static methods don’t require an object — which is exactly what the runtime needs at the entry point.

But then I realized that in C and C++, we don’t mention main() as static, yet it still executes. So, what’s the deal? 🤷‍♂️
Also, Python doesn’t even need a main() method to be executed. Curious, I did some research and discovered the difference:

C/C++, classes are not the core structure (with C not having classes at all), but in Java and C#, classes form the core structure of the program. These languages require a class to call a function, which is why the Main method is made static in Java and C#. (core structure in the sense everything has to be in classes)
As for Python, it is an interpreted language that executes code line by line, meaning there's no need for a defined entry point like Main() in Python.

While exploring this, I came across an interesting point:
“GCC is a compiler — it translates your C/C++ code into machine code that your CPU can execute directly. It doesn’t "run" your program like an interpreter — instead, it builds an executable that the OS can run.” 🖥️
This got me thinking, how do Java and C# programs execute?

I found out that Java and C# programs run on a runtime environment (A runtime environment is the software infrastructure that allows a program to execute. It provides the necessary services and resources to run the program). This made me question:
“Why do we need a runtime environment when we can execute our programs on the OS like C and C++?” 🤨

Answer to that thought:

When we execute a program on the OS:

• Memory Management: We need to handle memory management manually (e.g., garbage collection). With a runtime environment, it automatically handles garbage collection.

• Security: The runtime environment enhances security by providing type safety and sandboxing, ensuring safer execution of programs, while the OS only manages low-level permissions.

What is Sandboxing ?: Sandboxing is a security mechanism used to run code in a restricted and isolated environment.
It’s like saying:
"Here’s a playground (sandbox) where you can do whatever you want — but you can’t leave it and mess with the rest of the system." 🧸

Why Use a Runtime?

• A runtime environment ensures portability by allowing you to compile the code once, and then run the same bytecode across different operating systems, eliminating the need for separate compilation for each OS. 🌍

• Unlike the OS, which may result in crashes or core dumps, the runtime environment provides structured error handling through mechanisms like try/catch blocks, allowing for more controlled and predictable exception management. ⚠️

And with that, my flow of questions came to a halt for today... but I’m sure it will continue when I come across something else! 🚀