<\/p>\n\n\n\n
In C++, access modifiers<\/strong> are keywords used to define the level of access that members of a class (variables and methods) can have. They are essential for ensuring encapsulation<\/strong>, which is a core concept of Object-Oriented Programming (OOP). By using access modifiers, we control how the internal data of a class is accessed, modified, and protected.<\/p>\n\n\n\n Access modifiers<\/strong> in C++ include:<\/p>\n\n\n\n By controlling access, access modifiers help:<\/p>\n\n\n\n In this tutorial, we explored the three main access modifiers<\/strong> in C++:<\/p>\n\n\n\n By using these access modifiers, we can control data visibility, ensuring that class members are accessible in a controlled and secure manner. Access modifiers are fundamental in achieving encapsulation<\/strong> and data hiding<\/strong>, which are essential principles of object-oriented programming.<\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" What Are Access Modifiers? In C++, access modifiers are keywords used to define the level of access that members of a class (variables and methods) can have. They are essential for ensuring encapsulation, which is a core concept of Object-Oriented Programming (OOP). By using access modifiers, we control how the internal data of a class is accessed, modified, and protected. Access modifiers in C++ include: By controlling access, access modifiers help: Types of Access Modifiers Code Example class number {…<\/p>\n\n
private<\/code><\/strong>: Members are accessible only within the same class.<\/li>\n\n\n\nprotected<\/code><\/strong>: Members are accessible within the class and derived classes.<\/li>\n\n\n\npublic<\/code><\/strong>: Members are accessible from anywhere in the program.<\/li>\n<\/ul>\n\n\n\n\n
Types of Access Modifiers<\/strong><\/h3>\n\n\n\n
\n
private<\/code><\/strong>:\n\n
private<\/code> are accessible only within the same class. They are hidden from derived classes and external code.<\/li>\n\n\n\nprotected<\/code><\/strong>:\n\n
protected<\/code> are accessible within the same class and any derived (child) classes. However, they are not accessible by objects of the class.<\/li>\n\n\n\npublic<\/code><\/strong>:\n\n
public<\/code> are accessible from anywhere. This includes external code, objects, and even derived classes.<\/li>\n\n\n\nCode Exampl<\/strong>e<\/h3>\n\n\n\n
class number {
private:
int privateVar; \/\/ Private variable, accessible only within this class.
protected:
int protectedVar; \/\/ Protected variable, accessible within the class and derived classes.
public:
int publicVar; \/\/ Public variable, accessible from anywhere.
\/\/ Constructor to initialize the variables
number() {
privateVar = 10;
protectedVar = 20;
publicVar = 30;
}
\/\/ Public function to display values of all members
void display() {
cout << \"Private Variable: \" << privateVar << endl;
cout << \"Protected Variable: \" << protectedVar << endl;
cout << \"Public Variable: \" << publicVar << endl;
}
};
<\/code><\/pre>\n\n\n\nExplanation of the Base Class<\/strong><\/h4>\n\n\n\n
\n
privateVar<\/code>)<\/strong>:\n\n
privateVar<\/code> is declared private<\/code>, meaning it can only be accessed inside the number<\/code> class. It is hidden from both derived classes and external code.<\/li>\n\n\n\nprotectedVar<\/code>)<\/strong>:\n\n
protectedVar<\/code> is declared protected<\/code>, meaning it can be accessed within the number<\/code> class and any class derived from it (like the Derived<\/code> class).<\/li>\n\n\n\npublicVar<\/code>)<\/strong>:\n\n
publicVar<\/code> is declared public<\/code>, meaning it is accessible from anywhere in the program, including objects of the class, and even in derived classes.<\/li>\n\n\n\n\n
privateVar = 10<\/code>, protectedVar = 20<\/code>, publicVar = 30<\/code>).<\/li>\n<\/ul>\n<\/li>\n\n\n\ndisplay<\/code>)<\/strong>:\n\n
display()<\/code> function prints the values of the three variables to show how access modifiers impact the visibility of the class members.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n
\n\n\n\nDerived Class Code (
Derived<\/code> class)<\/strong><\/h4>\n\n\n\nclass Derived : public number {
public:
\/\/ Accessing protected variable in the derived class
void displayProtected() {
cout << \"Protected Variable (from Derived class): \" << protectedVar << endl;
}
};
<\/code><\/pre>\n\n\n\nExplanation of the Derived Class<\/strong><\/h4>\n\n\n\n
\n
number<\/code><\/strong>:\n\n
Derived<\/code> class inherits from the number<\/code> class using public inheritance. This means all public and protected members of the number<\/code> class are inherited by Derived<\/code>.<\/li>\n<\/ul>\n<\/li>\n\n\n\n\n
displayProtected()<\/code> function in the Derived<\/code> class prints the value of protectedVar<\/code>. This is allowed because protectedVar<\/code> is protected and can be accessed by derived classes.<\/li>\n<\/ul>\n<\/li>\n\n\n\n\n
privateVar<\/code><\/strong> is a private member of the number<\/code> class and cannot be accessed directly by the Derived<\/code> class. This demonstrates the limited access of private members.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\nMain Function Code<\/strong><\/h3>\n\n\n\n
int main() {
\/\/ Object of base class
number obj;
\/\/ Accessing public variable directly
cout << \"Public Variable: \" << obj.publicVar << endl;
\/\/ Displaying all variables using the public function
obj.display();
\/\/ Object of derived class
Derived derivedObj;
\/\/ Accessing protected variable via derived class
derivedObj.displayProtected();
return 0;
}
<\/code><\/pre>\n\n\n\nExplanation of the Main Function<\/strong><\/h4>\n\n\n\n
\n
obj<\/code> (Object of number<\/code>)<\/strong>:\n\n
obj<\/code> is an instance of the number<\/code> class. Using this object, we can access the public member publicVar<\/code> directly.<\/li>\n<\/ul>\n<\/li>\n\n\n\ndisplay()<\/code><\/strong>:\n\n
obj.display()<\/code> function is called, which prints the values of all three variables (private, protected, and public). Although privateVar<\/code> is private, it can still be accessed within the class through a public function.<\/li>\n<\/ul>\n<\/li>\n\n\n\nderivedObj<\/code> (Object of Derived<\/code>)<\/strong>:\n\n
derivedObj<\/code> is an instance of the Derived<\/code> class. Since Derived<\/code> inherits from number<\/code>, it can access the protected member protectedVar<\/code> through the displayProtected()<\/code> function.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n
\n\n\n\nOutput of the Code<\/strong><\/h3>\n\n\n\n
Public Variable: 30
Private Variable: 10
Protected Variable: 20
Public Variable: 30
Protected Variable (from Derived class): 20
<\/code><\/pre>\n\n\n\nExplanation of the Output<\/strong><\/h4>\n\n\n\n
\n
Public Variable: 30<\/code><\/strong>:\n\n
obj<\/code> object since it is a public member.<\/li>\n<\/ul>\n<\/li>\n\n\n\nPrivate Variable: 10<\/code><\/strong>:\n\n
display()<\/code> function. Although it is private, it can be accessed within the class.<\/li>\n<\/ul>\n<\/li>\n\n\n\nProtected Variable: 20<\/code><\/strong>:\n\n
display()<\/code> function. protectedVar<\/code> is accessible within the number<\/code> class.<\/li>\n<\/ul>\n<\/li>\n\n\n\nProtected Variable (from Derived class): 20<\/code><\/strong>:\n\n
displayProtected()<\/code> function in the Derived<\/code> class. The derived class can access protected members of the base class.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n
\n\n\n\nAccess Summary Table<\/strong><\/h3>\n\n\n\n
Access Modifier<\/strong><\/th> Access Inside Class<\/strong><\/th> Access in Derived Class<\/strong><\/th> Access via Object<\/strong><\/th><\/tr><\/thead> private<\/code><\/td>\u2705<\/td> \u274c<\/td> \u274c<\/td><\/tr> protected<\/code><\/td>\u2705<\/td> \u2705<\/td> \u274c<\/td><\/tr> public<\/code><\/td>\u2705<\/td> \u2705<\/td> \u2705<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n Conclusion<\/strong><\/h3>\n\n\n\n
\n
private<\/code><\/strong>: Restricts access to within the class.<\/li>\n\n\n\nprotected<\/code><\/strong>: Allows access within the class and derived classes, but not by external code.<\/li>\n\n\n\npublic<\/code><\/strong>: Grants access to members from anywhere in the program.<\/li>\n<\/ul>\n\n\n\n