fgets adds \0 or \n at the end of the input?

Question

I've some doubts about fgets. From what I know, it adds "\n" at the end of the string, and not "\0". So if I write this code:

fgets(buff,2,stdin);
printf("%s",buff);

So fgets reads two characters, I give as input "y", so buff should be "y\n". I'd expect printf to print y and add a line, while it prints "y" without adding a line. Can you explain why?

Answer 1

char * fgets ( char * str, int num, FILE * stream );

Reads characters from input stream and stores them as a C string into str until (num-1) characters have been read or either a newline or the end-of-file is reached, whichever happens first.

A newline character makes fgets stop reading, but it is considered a valid character by the function and included in the string copied to str.

A terminating null character ('\0') is automatically appended after the characters copied to str.