c언어 자료형의 크기

Microsoft Visual C++ recognizes the types shown in the table below.

Type Name	Bytes	Other Names	Range of Values
int	*	signed, signed int	System dependent
unsigned int	*	unsigned	System dependent
__int8	1	char, signed char	–128 to 127
__int16	2	short, short int, signed short int	–32,768 to 32,767
__int32	4	signed, signed int	–2,147,483,648 to 2,147,483,647
__int64	8	none	–9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
bool	1	none	false or true
char	1	signed char	–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
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	4	unsigned long int	0 to 4,294,967,295
enum	*	none	Same as int
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

A variable of __wchar_t designates a wide-character or multibyte character type. By default wchar_t is a typedef for unsigned short.

 

 

 

 

 

 

 

Sizes of Fundamental Types

Type	Size
bool	1 byte
char, unsigned char, signed char	1 byte
short, unsigned short	2 bytes
int, unsigned int	4 bytes
__intn	1, 2, 4, or 8 bytes depending on the value of n. __intn is Microsoft-specific.
long, unsigned long	4 bytes
float	4 bytes
double	8 bytes
long double1	8 bytes
long long	Equivalent to __int64.

¹   The representation of long double and double is identical. However, long double and double are separate types.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fundamental Types of the C++ Language

Category	Type	Contents
Integral	char	Type char is an integral type that usually contains members of the execution character set — in Microsoft C++, this is ASCII.
		The C++ compiler treats variables of type char, signed char, and unsigned char as having different types. Variables of type char are promoted to int as if they are type signed char by default, unless the /J compilation option is used. In this case they are treated as type unsigned char and are promoted to int without sign extension.
	bool	Type bool is an integral type that can have one of the two values true or false. Its size is unspecified.
	short	Type short int (or simply short) is an integral type that is larger than or equal to the size of type char, and shorter than or equal to the size of type int.
		Objects of type short can be declared as signed short or unsigned short. Signed short is a synonym for short.
	int	Type int is an integral type that is larger than or equal to the size of type short int, and shorter than or equal to the size of type long.
		Objects of type int can be declared as signed int or unsigned int. Signed int is a synonym for int.
	__intn	Sized integer, where n is the size, in bits, of the integer variable. The value of n can be 8, 16, 32, or 64. (__intn is a Microsoft-specific keyword.)
	long	Type long (or long int) is an integral type that is larger than or equal to the size of type int.
		Objects of type long can be declared as signed long or unsigned long. Signed long is a synonym for long.
Floating	float	Type float is the smallest floating type.
	double	Type double is a floating type that is larger than or equal to type float, but shorter than or equal to the size of type long double.1
	long double1	Type long double is a floating type that is equal to type double.
Wide-character	__wchar_t	A variable of __wchar_t designates a wide-character or multibyte character type. By default, wchar_t is a typedef for unsigned short; see /Zc:wchar_t for more information. Use the L prefix before a character or string constant to designate the wide-character-type constant.

¹   The representation of long double and double is identical. However, long double and double are separate types.

 

 

 

자주보는 DWORD와 WORD는

 

typedef unsigned long DWORD;

typedef unsigned short int WORD;

 

로 타입변환되어 있음.