Basic data types for C languages

C There are three categories of data types that languages allow .

(1) basic type . The most basic data types that cannot be divided include integer, floating point (single precision), double, character, no value, logical, and plural types. The base type typically represents a single data.

(2) construction type . A type constructed by a known base type through certain construction methods, including arrays, structs, unions, enumeration types, and so on. A constructed type typically represents a batch of data.

(3) pointer type . Pointers can point to memory addresses, access to high efficiency, to construct various forms of dynamic or recursive data structures, such as linked lists, trees and so on.

1.1 Basic data Types

1 . Base data type and its keywords

The 7 basic data types provided by the C99 standard and their corresponding keywords are shown in the table.

Data type	Key words	Data type	Key words
Character type	Char	No value type	void
Integral type	Int	Logic type	_bool
floating point ( single precision) type	Float	Plural type	_complex_imaginary
Double-precision Type	Double

Character Type : Describes a single character;

integer: Describes integers, integers are accurately represented on a computer;

floating point, double type : Describe real numbers, real numbers are generally approximate on a computer, the approximation of floating-point is relatively low, and the approximation of double-precision is relatively high.

No value type : No specific value, usually used to describe a non-formal parameter or a non-return value of the C function, as well as a non-directional pointer.

Logical: describes the logic true (its value is 1) and the logical false (its value is 0).

plural type: describes complex numbers (_complex) and pure Imaginary (_imaginary).

You must include the header file stdbool.h when you use the logical type, and you must include the header file complex.h when you use the plural type.

2 . How the base data type is stored and the range of values, the extension of the base data type

Type	Length/byte	Range of values	Storage mode
Char	1	-128~127	Signed binary complement form
[Signed]char	1	-128~127
unsigned char	1	0~255
short [int]	2	-32768~32767
unsigned short [int]	2	0~65535
Int	4	-2147483648~2147483647	Fixed-point signed binary complement form
[Signed] int	4	-2147483648~2147483647
unsigned [int]	4	0~4294967295
long [int]	4	-2147483648~2147483647
[Signed] long [INT]	4	-2147483648~2147483647
unsigned long [int]	4	0~4294967295
Float	4	-3.4*10^38~3.4*10^38	Storage in floating-point form
Double	8	-1.798*10^308~1.798*10^308	Storage in floating-point form
Long double	8	-1.798*10^308~1.798*10^308

Short Int<=int<=long Int<=long Long int

Float<=double<=long Double

Basic data types for C languages