2, print format

Symbol format
% @ object
%zd NSInteger
%lx CFIndex
%tu NSUInteger
%i Int
%u Unsinged int
%hu Unsigned short
%% % symbol
%p Pointer
%02ld Print two digit plastic, insufficient front fill zero
%s, PRETTY_FUNCTION or __FUNCTION__ Print method name
%f Floating point, double word
%04X Four bit, sixteen hex