32-bit, 64-bit operating system base data type byte size

The length of the basic data type in the C language:

Under 32 bits:

Char:1 bytes (unchanged)

* (pointer variable): 4 bytes (32-bit machine's addressing space is 4 bytes.) Similarly 64-bit compilers) (change)

Short Int:2 bytes (unchanged )

Int:4 bytes (unchanged )

Unsigned int:4 bytes (unchanged )

Float:4 bytes (unchanged )

Double:8 bytes (unchanged )

Long:4 bytes (varies )

Unsigned long:4 bytes (change *, is actually the address length value of the addressing control)

Long Long:8 bytes (unchanged )

Under 64 bits:

Char 1 bytes (unchanged )

* (pointer variable): 8 bytes

Short Int:2 bytes (unchanged )

Int:4 bytes (unchanged )

Unsigned int:4 bytes (unchanged )

Float:4 bytes (unchanged )

Double:8 bytes (unchanged )

Long:8 bytes (varies )

Unsigned long:8 bytes (change * is actually the address length value of the addressing control)

Long Long:8 bytes (unchanged )

Except that * and long vary with the operating system Zichang, others are fixed (32-bit vs. 64)

BOOL 1 bytes char 1 byte int 4 bytes float 4 bytes Doubl 8 bytes Long Long 8 bytes

In OC:

64-bit system (this machine is not a 32-bit system can not be tested):

NSString 8-bit

Nsinteger 8-bit (signed)

Nsuinteger 8 bits (unsigned, no negative numbers)

Many variables in OC are actually pointers, so many of the 64-bit systems are 8-bit,

By the way, NSNumber,Nsinteger is the underlying type, but NSNumber is a class. If you want to Nsmutablearray or

nsmutabledictionary Store A value, the direct use of Nsinteger is not, to first convert to NSNumber class,

This article refers to the http://blog.csdn.net/totogo2010/article/details/7655908

32-bit, 64-bit operating system base data type byte size