Type

 

C

Language

Standard Library

Type support

Dynamic memory management

Error handling

Program utilities

Date and time utilities

Strings library

Algorithms

Numerics

Input/output support

Localization support

Thread support (C11)

Atomic operations (C11)

 

C language

General topics
Preprocessor
Comments
Keywords
Escape sequences
History of C
Flow control
Conditional execution statements
if statement	switch statement
Iteration statements
for loop	while loop do-while loop
Jump statements
continue statement break statement	goto statement return statement
Functions
function declaration
inline specifier
Types
fundamental types pointer types compound types enumeration types	union types function types
Specifiers
cv specifiers
storage-class specifiers
alignas specifier (C99)
function specifiers (C99)
Literals
integer literals character literals floating-point literals	string literals boolean literals(C99)
Expressions
order of evaluation
operators
operator precedence
alternative operators
Utilities
typedef declaration
attributes (C99)
casts
Miscellaneous
Inline assembly

 

Objects, functions, and expressions have a property called type. Type determines the interpretation of an otherwise generic sequence of bits comprising the value of an object or the value returned from a function or expression. Type also determines which operations are valid.

Type classification

The C type system is an heirarchy of types and type categories:

• complete type (having sufficient information to determine the size of an object of that type)

• object type (a type that describes an object)

• scalar type

• arithmetic type

• integer type

• char
• signed integer type

• standard signed integer type

• signed char
• short int
• int
• long int
• long long int

• extended signed integer type

• unsigned integer type

• standard unsigned integer type

• unsigned char
• unsigned short int
• unsigned int
• unsigned long int
• unsigned long long int
• _Bool

• extended unsigned integer type

• enumerated type (each distinct enumeration)

• floating type

• real floating type

• float
• double
• long double

• complex type

• float _Complex
• double _Complex
• long double _Complex

• pointer type

• pointer to object
• pointer to function
• pointer to incomplete type

• derived type (constructed recursively from the object and function types)

• aggregate type

• array type
• struct type

• union type
• function type
• pointer type (referenced type)
• atomic type (_Atomic)

• function type (a type that describes a function)

• incomplete type (lacking sufficient information to determine the size of an object of that type)

• void (cannot be completed)
• incomplete array type (array size is unknown)
• incomplete struct type
• incomplete union type

Miscellaneous type categories:

• atomic, qualified and unqualified type - _Atomic, const, volatile, restrict
• basic type (complete type)

• char
• signed and unsigned integer type
• floating type

• character type

• char
• signed char
• unsigned char

• corresponding real type - always a real floating type

• real floating type - same type
• complex type - type given by deleting the keyword _Complex from the type name

• derived declarator type

• array type
• function type
• pointer type

• element type - type of the object used as an array element
• extended integer type

• extended signed integer type
• extended unsigned integer type

• real type

• integer type
• real floating type

• referenced type - pointer type derived from a function type or an object type
• standard integer type

• standard signed integer type
• standard unsigned integer type

• type category - outermost derivation of a derived type or the type itself

See also

C++ documentation for C++ Type