C + + class scope and visible fields

data members and function members defined in a class are scoped to the entire class, which is visible only in the class (which contains the definition part of the class and the implementation part of the out-of-class function) and is invisible outside the class. If a "masking" phenomenon occurs, the members of the class have a small and scoped visible field, but at this point they can access the class member in the form of the this pointer or the " class Name::", which is similar to using "::" To access the global variable.

Example:

extern int x=100;

extern int z=100;

Class Example

{

int x;

int y;

Public:

Example (int x,int y)

{}

void print (int x)

{

cout<< "parameter overrides member x variable and Global x variable" <<x<<end1; parameter x covers global variables and local variables X

cout<< "member x variable" << (this->x) <<end1;

cout<< "member x variable" <<Example::x<<end1;

cout<< "Global x Variable" << (:: x) <<end1; Accessing Global variables X

cout<< "Global z variable" <<z<<end1; No formal parameter makes a mask on global variable z, and direct access to Z

}

}

int main ()

(

Example e;

X.print (5);

return 0;

)

Output Result:

5

0

0

100

200

C + + class scope and visible fields