How many data types are supported by c?

Answer 1

The fundamental types of C:

A Boolean type: bool

A character type: char

An integer type: int

A floating-point type: float, double and long double

No type: void

The character and integer types can be modified using the signed/unsigned and short/long type modifiers. If no type is specified with a modifier, int is assumed. E.g., a short implies a short int.

In addition, a user can define additional types:

Data structures: e.g., struct and union

Enumeration types: enum

Also, for any given type, T, a user can define other types using declarator operators:

A pointer type: T*

An array type: T[]

The Boolean, character and integer types are collectively called integral types. The integral and floating-point types are collectively called arithmetic types. Fundamental types, pointers and arrays are collectively called built-in types. Enumerations and data structures are called user-defined types. Note that all user-defined types must be declared by the user before they can be used, whereas all built-in types are available for use without prior declaration.

The integral and floating point types are provided in a variety of sizes to give the programmer a choice of the amount of storage consumed, the precision and the range available for computations. The assumption is that a computer provides bytes for holding characters, words for holding and computing integer values, some entity for floating-point computation and addresses for referring to all these entities. The fundamental types together with pointers and arrays present these machine-level notions to the programmer in a reasonably implementation-independent manner.

For most applications, we could use bool for logical values, char for characters, int for integer values, and double for floating point values. The remaining fundamental types are variations for optimisations, special needs and compatibility that are best ignored until such needs arise.