---
# System prepended metadata

title: Chapter 1

---

# Chapter 1

Teach programming using the language C. It is an old language but it is still used today. It is bare bones, without much abstraction and complexity.

## Hello World
```c
#include <stdio.h>

main() {
  printf("Hello World");
}
```

Run it in https://repl.it c programming language

## Most minimal C program which does nothing
```c
main() {

}
```

The run is always run from top to bottom by the computer.

This code does nothing but it runs successfully.
any C program must have this `main()` written and have curly braces `{}` after it.

We write the content of the program in between the curly braces. The style of curly braces is the choice of the programmer.

You can write it as
```c
main()
{

}
```

It is up-to the programmer.


## Now we'll write a basic program which prints something to the screen

```c
#include <stdio.h>

main() {
  printf("Hello World");
}
```

`printf` is a function provided by the line `#include <stdio.h>`. If you ever want to use `printf`, you have to add this line also at the top of the program. We'll get to what this line means later on.

It is almost ritualistic to print the message `Hello World` whenever you try a new programming language.

