Converting integer from 0 to 255 ( 1 byte ) into NSDATA

Question

对于某种基于套接字的应用程序，我只需要1个字节，我找不到创建它的方法。

Answer 1

unsigned char mydata = 3;
[NSMutableData dataWithBytes:&mydata length:sizeof(mydata)];

NSData reference , unsigned char is used to save 1 byte.