//数据类型:
//整形(int、short int、long int、unsigned int、unsigned short、unsigned long)
NSLog(@"整形:");
NSLog(@"%lu",sizeof(int));//整形4个字节
NSLog(@"%lu",sizeof(short int));//短整形2
NSLog(@"%lu",sizeof(long int));//长整形8
NSLog(@"%lu",sizeof(unsigned int));//无符号整形4
NSLog(@"%lu",sizeof(unsigned short));//无符号短整形2
NSLog(@"%lu",sizeof(unsigned long));//无符号长整形8
//实形(float 、double 、long double)
NSLog(@"实形:");
NSLog(@"%lu",sizeof(float));//浮点形4
NSLog(@"%lu",sizeof(double));//双精度形8
NSLog(@"%lu",sizeof(long double));//长精度形16
//字符型和字符串形
char a='a';
char b=100;
NSLog(@"%c,%c",a,b);
NSLog(@"%i,%i",a,b);
NSLog(@"我是字符串");//字符串形:@“我是字符串”