friend class

1. Global functions and class member function conversionsMutual transformation of global functions and member functions: you only need to modify a pointer to this class .#include using namespace Std;class test{public:test (int a, int b) {this->a = A;

Scope and visibility of identifiers A scope is an area in which an identifier is valid in the body of the program. Scope classification Function prototype scope Local scope (block scope) Class scope File scope

Common methods of data sharing global variables have great limitations and undermine encapsulation. Static members, as a data member of a class, can implement data sharing between multiple objects, and the use of static data members does not return

The question is raised:We already know that classes have the properties of encapsulation and information hiding. Only member functions of a class can access private members of a class, and other functions in the program cannot access private members.

Digest#ifndef _digestcalc_h#define _digestcalc_h/**********************************/* Use example: (SM3 algorithm)/*digestcalc hashcl;/* Hashcl. Init (DIGESTCALC::ALG_ID::SM3);/*hashcl. Update (IN,INL);/* vector out (hashcl. Gethashlength

12.3 Class Scopes 1. In member functions that are defined outside the class, the formal parameter list and the member function body appear after the member name. These are defined in a class scope, so you can refer to other members without

Objective And to the end of the year, also quiet heart to write code, we are very impetuous, turn out the classic "Paladin" play for a while, and play Big Boss, first save the file bar. This is my habit, before playing Big Boss, have to save a file,

Each person and thing in a different state will have a different performance (action), and a state will be in different manifestations to the next different states (state). One of the simplest examples of life is this: the subway entrance, if you

A variable in a C + + class that has the following keyword as the modifier. 1. Public: Access is available anywhere in the program. 2 Protected: Only the class itself and its derived classes and their friend functions, the friend class can access.

=======================================================Original articles, reproduced please indicate the program small Weng @ Blog Park, Mail [email Protected],jilon, welcome you and I in the c/c++/objective-c/machine vision and other fields to

1, why to introduce friend function: reduce system overhead and increase efficiency when data sharing between classes is implementedC + + use friend modifier, you can let some of the functions you set to operate on these protection data, avoid the

Two of the recommendations are to be seen, each has strengthsOriginal 1:http://cache.baiducontent.com/c?m= 9f65cb4a8c8507ed4fece763105392230e54f7636d918d027fa3c215cc7902155a66e1b821201b19d2c47c640aae5e5c9daa702d691765eadb9e871a8 3e6c37138895723061f91

SerializationOverview Requirement Other Implementation Solutions Here, we use terminology Serialization)To represent a group of original C ++ data structures as byte streams for reversible analysis. Such a system

Level of visibilityThe C + + class provides the encapsulation of data structures and algorithms, and the corresponding 3 levels of visibility. They define different visibility: Public: visible in methods of the current class and subclass,

The following points apply to all c ++ programmers. The reason why I say they are the most important is that you often cannot find them in C ++ books or websites. For example, the pointer to a Member is not to be mentioned in many documents, but

    In the previous article, we analyzed the strong pointer sp in the Android smart pointer. In this article, we will analyze the weak pointer wp. Why do we need a weak pointer wp? Consider the following scenario: CParent and CChild. A smart pointer

Simple startThe Chinese interpretation of serialization is "serializing", "serialization", or "persistence", which means to save the objects in the memory to the disk, when the program runs again, it reads the files on the disk and restores the

Data Structure BASICS (12)-Design and Implementation of two-way circular linked list Features of two-way linked list operation: (1) "query" is the same as a single-chain table; (2) When "insert" and "delete", you must modify the pointer in both

1, friend Yuan　　after adopting the mechanism of the class, the data hiding and encapsulation are realized, the data members of the class are generally defined as private members, and the member functions are generally defined as public, and the

CHAP5:The dangling else:else is matched with its nearest unmatched if, or it is made into a block with curly braces.Switch (shape/character) {case shaping/character: Break;default:break;} It is best to use curly braces in case to define local