%@ Objective-C object, printed string returned by descriptionWithLocale 
    %% '%' character.
    %d, %D Signed 32-bit integer (int).
    %u, %U Unsigned 32-bit integer (unsigned int).
    %x Unsigned 32-bit integer (unsigned int), printed in hex using 0-9 and a–f.
    %X Unsigned 32-bit integer (unsigned int), printed in hex using 0-9 and A–F.
    %o, %O Unsigned 32-bit integer (unsigned int), printed in octal.
    %f 64-bit float (double).
    %e 64-bit float (double), e exponent.
    %E 64-bit float (double), E exponent.
    %g 64-bit float (double), %e if exponent < – 4 or >= to the precision, %f o.w.
    %G 64-bit float (double), %E if exponent < – 4 or >= to the precision, %f o.w.
    %c 8-bit unsigned character 
    %C 16-bit Unicode character 
    %s Null-terminated array of 8-bit unsigned characters. 
    %S Null-terminated array of 16-bit Unicode characters.
    %p Void pointer (void *), printed in hex with the digits 0–9 and a–f, with a leading 0x.
    %a 64-bit float, leading 0x and one hex before decimal pt using p as exp.
    %A 64-bit float, leading 0X and one hex before decimal pt using P as exp.
    %F 64-bit float, printed in decimal notation.