# 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.