Next, we will look at built-in data types. All but the most trivial programs store and manipulate information on a computer. In your GENE 121 and MTE 140 courses, you learned how to store and manipulate data using C++. This is just a quick review of those features that overlap between C and C++, starting with variables.

To store information on a computer, it is ultimately necessary to convert the data into ones and zeros: a novel is converted into unicode characters, each of which is made up of sixteen bits while a photograph is approximated using a discretizations which is then approximated using the Fourier cosine transform, the coefficients of which are stored on the computer.

There are fewer than two dozen built-in data types: formats for information for which the library is already aware: these are to store characters, integers on restricted ranges, memory-related and real numbers on restricted ranges with restricted precision.

bool 8 bits

char	8 bits	0 to 256
signed char	8 bits	-128 to 127

A special wide character is available in the library wchar.h and the type is wchar_t. It is used for unicode characters.

short	16 bits	-32768 to 32767
unsigned short	16 bits	0 to 65535
int	32 bits	-2147483648 to 2147483647
unsigned int	32 bits	0 to 4294967295
long	64 bits	-9223372036854775808 to 9223372036854775807
unsigned long	64 bits	0 to 18446744073709551615
long long	64 bits	-9223372036854775808 to 9223372036854775807
unsigned long long	64 bits	0 to 18446744073709551615

float	32 bits
double	64 bits
long double	128 bits

size_t	64 bits	0 to 18446744073709551615
ptrdiff_t	64 bits