C++ 数据类型的表示范围

For 32-bit and 64-bit compilers, Microsoft Visual C++ recognizes the types shown in the table below. Note that the following type also have unsigned forms:

• int (unsigned int)

• __int8 (unsigned __int8)

• __int16 (unsigned __int16)

• __int32 (unsigned __int32)

• __int64 (unsigned __int64)

• short (unsigned short)

• long (unsigned long)

• long long (unsigned long long)

Type NameBytesOther NamesRange of Values

int

4

signed

–2,147,483,648 to 2,147,483,647

unsigned int

4

unsigned

0 to 4,294,967,295

__int8

1

char

–128 to 127

unsigned __int8

1

unsigned char

0 to 255

__int16

2

short, short int, signed short int

–32,768 to 32,767

unsigned __int16

2

unsigned short, unsigned short int

0 to 65,535

__int32

4

signed, signed int, int

–2,147,483,648 to 2,147,483,647

unsigned __int32

4

unsigned, unsigned int

0 to 4,294,967,295

__int64

8

long long, signed long long

–9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

unsigned __int64

8

unsigned long long

0 to 18,446,744,073,709,551,615

bool

1

none

false or true

char

1

none

–128 to 127 by default

0 to 255 when compiled with /J

signed char

1

none

–128 to 127

unsigned char

1

none

0 to 255

short

2

short int, signed short int

–32,768 to 32,767

unsigned short

2

unsigned short int

0 to 65,535

long

4

long int, signed long int

–2,147,483,648 to 2,147,483,647

unsigned long

4

unsigned long int

0 to 4,294,967,295

long long

8

none (but equivalent to __int64)

–9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

unsigned long long

8

none (but equivalent to unsigned __int64)

0 to 18,446,744,073,709,551,615

enum

varies

none

See Remarks.

float

4

none

3.4E +/- 38 (7 digits)

double

8

none

1.7E +/- 308 (15 digits)

long double

same as double

none

same as double

wchar_t

2

__wchar_t

0 to 65,535

reference: http://msdn.microsoft.com/en-us/library/s3f49ktz(v=vs.80).aspx