C Data Types

c_data_types.md

C Data Types

Type	Explanation	Minimum size (bytes)	Minimum range	Format specifier
char	Smallest addressable unit of the machine that can contain basic character set. It is an integer type. Actual type can be either signed or unsigned. It contains CHAR_BIT bits.	1	[−127, +127]	%c
signed char	Of the same size as char, but guaranteed to be signed.	1	[−127, +127]	%c (or %hhi for numerical output)
unsigned char	Of the same size as char, but guaranteed to be unsigned.	1	[0, 255]	%c (or %hhu for numerical output)
short short int signed short signed short int	Short signed integer type.	2	[−32,767, 32,767]	%hi or %hd
unsigned short unsigned short int	Short unsigned integer type.	2	[0, 65,535]	%hu
int signed signed int	Basic signed integer type.	2	[−32,767, 32,767]	%i or %d
unsigned unsigned int	Basic unsigned integer type.	2	[0, 65,535]	%u
long long int signed long signed long int	Long signed integer type.	4	[−2,147,483,647, 2,147,483,647]	%li or %ld
unsigned long unsigned long int	Long unsigned integer type.	4	[0, 4,294,967,295]	%lu
long long long long int signed long long signed long long int	Long long signed integer type. The range is specified since the C99 version of the standard.	8	[−9,223,372,036,854,775,807, 9,223,372,036,854,775,807]	%lli or %lld
unsigned long long unsigned long long int	Long long unsigned integer type. The range is specified since the C99 version of the standard.	8	[0, 18,446,744,073,709,551,615]	%llu
float	Real floating-point type, usually referred to as a single-precision floating-point type.	4	[3.4E +/- 38]	(Converting from text:) %f %F %g %G %e %E %a %A
double	Real floating-point type, usually referred to as a double-precision floating-point type.	8	[1.7E +/- 308]	%lf %lF %lg %lG %le %lE %la %lA
long double	Real floating-point type, usually mapped to an extended precision floating-point number format.	16, 12 or 10	[3.4E +/- 4932]	%Lf %LF %Lg %LG %Le %LE %La %LA

• float: Actual properties unspecified (except minimum limits); however, on most systems, this is the IEEE 754 single-precision binary floating-point format (32 bits). This format is required by the optional Annex F "IEC 60559 floating-point arithmetic".
• double: Actual properties unspecified (except minimum limits); however, on most systems, this is the IEEE 754 double-precision binary floating-point format (64 bits). This format is required by the optional Annex F "IEC 60559 floating-point arithmetic".
• long double: Actual properties unspecified. It can be either x86 extended-precision floating-point format (80 bits, but typically 96 bits or 128 bits in memory with padding bytes), the non-IEEE "double-double" (128 bits), IEEE 754 quadruple-precision floating-point format (128 bits), or the same as double. See the article on long double for details.
• Whether it uses 32-bit or 64-bit (LP32, ILP32, LLP64, LP64) data model could decide the size and range of the data.
• The range varies depending on the language and data model (e.g. [−127, +127] could be [−128, +127])

Reference: Wikipedia: C data types