# Lession 1 : The first C programming.

```c
#include stdio.h

int main()
{
    printf("Hello World");

    return 0;
}
```

According to the C90 and C99 standard main should return int.

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

stdio.h : "standard library C". This is written by the technical committee

main.c -&gt; main.i (open the standard library)(full code from scratch) -&gt; main.s(assembly) -&gt; main.o (machine code)

```c
int main()
{
    printf("Hello World \n");
    printf("Today is a good day");
}
```

\\ : it's the escape character

n : it's the new line

\\n : it's the escape sequence

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1695822363297/fee8096a-66e1-459c-bef8-f676eb1d5cd7.png align="center")

/r : move the curso back to the beginning of the line

```c
#include <stdio.h>
int main (){
    printf("David says , \" Programming is fun !\"\n");
    printf("**Conditions apply , \"Offers valid until tomorrow\"\n");
    printf("C:\\My computer\\My folder\n");
    printf("D:/My documents/My file\n");
    printf("This is a triple quoted string \"\"\" This month has 30 days \"\"\"");
}
```