格式化输出

八进制格式化输出

NSLog(@"%o",15);
NSLog(@"%#o",15)

输出
2016-04-12 23:36:14.093 MyTest[43037:539029] 17
2016-04-12 23:36:14.094 MyTest[43037:539029] 017

十六进制格式化输出

NSLog(@"%x",15);
NSLog(@"%#x",15);

输出
2016-04-12 23:36:14.094 MyTest[43037:539029] f
2016-04-12 23:36:14.094 MyTest[43037:539029] 0xf