Home Backend Development C++ What does ::and: mean in c++

What does ::and: mean in c++

Apr 26, 2024 pm 03:45 PM
c++ Scope

In C, :: (scope resolution operator) is used to access global variables, static members and specified namespaces, while :: (member access operator) is used to access members of a class or structure .

What does ::and: mean in c++

The meaning of :: and: in C

In C programming, :: and: are both operations symbols, respectively representing different meanings:

:: (scope resolution operator)

  • Access global or static member variables and functions
  • Specify the namespace of a class or object
  • Reference hidden or overloaded names

Example:

int x; // 全局变量

class MyClass {
public:
    int y; // 成员变量
    void print() {
        cout << MyClass::x << " " << y; // 访问全局变量和成员变量
    }
};
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: (Member access operator)

  • Access class or structure member variables or functions
  • Members pointing to objects
  • Indirect access pointer members

Example:

struct Point {
    int x;
    int y;
};

Point p;
p.x = 10; // 访问成员变量
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Summary

:: Used to access members in different namespaces or classes , while: is used to access members of a class. These two operators are very important in C, and understanding them is crucial to writing efficient code.

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