cheat sheets.

%b    => Binary integer
%c    => Single character
%d    => Decimal integer
%e    => Decimal integer displayed in exponential form
%f    => Floating point number
%g    => Same as %e if exponent is less than -4, %f otherwise
%o    => Octal integer
%s    => String
%u    => Unsigned decimal integer
%x    => Hexadecimal integer
%02d  => 0 padded two digits
%.02f => round to the hundredths