The role of a colon (:) in C + +

1. Colon (:) usage

(1) Represents the definition of a bit field within a mechanism (that is, the variable occupies several bit spaces)

typedef struct _xxx{

unsigned char a:4;

unsigned char c;

} ; Xxx

(2) The colon at the back of the constructor functions as a method of assigning a value to a member variable, initializing the list, and more appropriate for the const type of the member variable.

struct _xxx{

_xxx (): Y (0xc0) {}

};

(3) Public: and private: The following colon, which indicates that all the members defined later are publicly or privately held until the next "common:" or "Private:" appears. "Private:" is handled by default.

(4) The class name followed by a colon is used to define the inheritance of the class.

Class derived class Name: Inheritance mode base class name

{

Members of derived classes

};

Inheritance mode: Public, private, and protected, default processing is public.

The role of a colon (:) in C + +