By now, you are quite familiar with the public keyword that appears in all of our class examples:
Example
class MyClass { // The class
public: // Access specifier
// class members goes here
};
public: // Access specifier
// class members goes here
};
The
public keyword is an access specifier. Access specifiers define how the members (attributes and methods) of a class can be accessed. In the example above, the members are public - which means that they can be accessed and modified from outside the code.
However, what if we want members to be private and hidden from the outside world?
In C++, there are three access specifiers:
public- members are accessible from outside the classprivate- members cannot be accessed (or viewed) from outside the classprotected- members cannot be accessed from outside the class, however, they can be accessed in inherited classes. You will learn more about Inheritance later.
In the following example, we demonstrate the differences between public and private members:
Example
class MyClass {
public: // Public access specifier
int x; // Public attribute
private: // Private access specifier
int y; // Private attribute
};
int main() {
MyClass myObj;
myObj.x = 25; // Allowed (public)
myObj.y = 50; // Not allowed (private)
return 0;
}
public: // Public access specifier
int x; // Public attribute
private: // Private access specifier
int y; // Private attribute
};
int main() {
MyClass myObj;
myObj.x = 25; // Allowed (public)
myObj.y = 50; // Not allowed (private)
return 0;
}
Note: By default, all members of a class are private if you don't specify an access specifier:
Example
class MyClass {
int x; // Private attribute
int y; // Private attribute
};
int x; // Private attribute
int y; // Private attribute
};
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