Classes and Structs (C++)

 

The latest version of this topic can be found at Classes and Structs (C++).

This section introduces C++ classes and structs. The two constructs are identical in C++ except that in structs the default accessibility is public, whereas in classes the default is private.

Classes and structs are the constructs whereby you define your own types. Classes and structs can both contain data members and member functions, which enable you to describe the type's state and behavior.

The following topics are included:

• class

• struct

• Class Member Overview

• Member Access Control

• Inheritance

• Static Members

• User-Defined Type Conversions

• Mutable Data Members (mutable specifier)

• Nested Class Declarations

• Anonymous Class Types

• Pointers to Members

• this Pointer

• C++ Bit Fields

The three class types are structure, class, and union. They are declared using the struct, class, and union keywords (see Defining Class Types). The following table shows the differences among the three class types.

For more information on unions, see Unions. For information on managed classes and structs, see Classes and Structs.

Access Control and Constraints of Structures, Classes and Unions

Structures	Classes	Unions
class key is struct	class key is class	class key is union
Default access is public	Default access is private	Default access is public
No usage constraints	No usage constraints	Use only one member at a time

See Also

C++ Language Reference