Objective-c格式化输出格式

Objective-c格式化输出格式:

%@	Objective-C object, printed as the string returned by descriptionWithLocale: if available, or description otherwise. Also works with CFTypeRef objects, returning the result of the CFCopyDescription function.
%%	'%' 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 hexadecimal using the digits 0–9 and lowercase a–f.
%X	Unsigned 32-bit integer (unsigned int), printed in hexadecimal using the digits 0–9 and uppercase A–F.
%o, %O	Unsigned 32-bit integer (unsigned int), printed in octal.
%f	64-bit floating-point number (double).
%e	64-bit floating-point number (double), printed in scientific notation using a lowercase e to introduce the exponent.
%E	64-bit floating-point number (double), printed in scientific notation using an uppercase E to introduce the exponent.
%g	64-bit floating-point number (double), printed in the style of %e if the exponent is less than –4 or greater than or equal to the precision, in the style of %f otherwise.
%G	64-bit floating-point number (double), printed in the style of %E if the exponent is less than –4 or greater than or equal to the precision, in the style of %f otherwise.
%c	8-bit unsigned character (unsigned char), printed by NSLog() as an ASCII character, or, if not an ASCII character, in the octal format \\ddd or the Unicode hexadecimal format\\udddd, where d is a digit.
%C	16-bit Unicode character (unichar), printed by NSLog() as an ASCII character, or, if not an ASCII character, in the octal format \\ddd or the Unicode hexadecimal format \\udddd, where d is a digit.
%s	Null-terminated array of 8-bit unsigned characters. Because the %s specifier causes the characters to be interpreted in the system default encoding, the results can be variable, especially with right-to-left languages. For example, with RTL, %s inserts direction markers when the characters are not strongly directional. For this reason, it’s best to avoid %s and specify encodings explicitly.
%S	Null-terminated array of 16-bit Unicode characters.
%p	Void pointer (void *), printed in hexadecimal with the digits 0–9 and lowercase a–f, with a leading 0x.
%a	64-bit floating-point number (double), printed in scientific notation with a leading 0x and one hexadecimal digit before the decimal point using a lowercase p to introduce the exponent.
%A	64-bit floating-point number (double), printed in scientific notation with a leading 0X and one hexadecimal digit before the decimal point using a uppercase P to introduce the exponent.
%F	64-bit floating-point number (double), printed in decimal notation.

h	Length modifier specifying that a following d, o, u, x, or X conversion specifier applies to ashort or unsigned short argument.
hh	Length modifier specifying that a following d, o, u, x, or X conversion specifier applies to asigned char or unsigned char argument.
l	Length modifier specifying that a following d, o, u, x, or X conversion specifier applies to along or unsigned long argument.
ll, q	Length modifiers specifying that a following d, o, u, x, or X conversion specifier applies to along long or unsigned long long argument.
L	Length modifier specifying that a following a, A, e, E, f, F, g, or G conversion specifier applies to a long double argument.
z	Length modifier specifying that a following d, o, u, x, or X conversion specifier applies to asize_t or the corresponding signed integer type argument.
t	Length modifier specifying that a following d, o, u, x, or X conversion specifier applies to aptrdiff_t or the corresponding unsigned integer type argument.
j	Length modifier specifying that a following d, o, u, x, or X conversion specifier applies to aintmax_t or uintmax_t argument.

NSInteger	%ld or %lx	Cast the value to long.
NSUInteger	%lu or %lx	Cast the value to unsigned long.
CGFloat	%f or %g	%f works for floats and doubles when formatting; but note the technique described below for scanning.
CFIndex	%ld or %lx	The same as NSInteger.
pointer	%p or %zx	%p adds 0x to the beginning of the output. If you don't want that, use%zx and no typecast.

摘自Programming Guide for Cocoa文档