Added documentation page of C++ access modifier: protected

content/cpp/concepts/access-modifiers/terms/protected/protected.md

@@ -0,0 +1,79 @@
+---
+Title: 'Protected'
+Description: 'Allows class members to be accessed within their class and by derived classes.'
+Subjects:
+  - 'Code Foundations'
+  - 'Computer Science'
+Tags:
+  - 'Classes'
+  - 'Encapsulation'
+  - 'Inheritance'
+CatalogContent:
+  - 'learn-c-plus-plus'
+  - 'paths/computer-science'
+---
+
+In C++, the **`protected`** access specifier is used to define the accessibility of [class](https://www.codecademy.com/resources/docs/cpp/classes) members. Members declared as `protected` are accessible within the class itself and by its derived classes (subclasses).
+
+This approach balances [encapsulation](https://www.codecademy.com/resources/docs/cpp/encapsulation) and [inheritance](https://www.codecademy.com/resources/docs/cpp/inheritance) by restricting access while enabling derived classes to extend functionality.
+
+## Syntax
+
+The following syntax defines a base class with two `protected` members that can be accessed from derived classes:
+
+```pseudo
+class BaseClass {
+protected:
+  // Protected members
+  int myVar;
+  void myFunc();
+};
+```
+
+## Example
+
+The following example demonstrates the use of the `protected` access specifier in C++:
+
+```cpp
+#include <iostream>
+using namespace std;
+
+// Base class
+class BaseClass {
+protected:
+  int myVar;
+
+  void myFunc() {
+    cout << "Accessing protected function from BaseClass" << endl;
+  }
+};
+
+// Derived class
+class DerivedClass : public BaseClass {
+public:
+  void useProtectedMembers() {
+    myVar = 10; // Accessing protected variable
+    cout << "Protected variable value: " << myVar << endl;
+    myFunc();   // Accessing protected function
+  }
+};
+
+int main() {
+  DerivedClass obj;
+  obj.useProtectedMembers();
+
+  // The following lines will cause compilation errors if uncommented
+  // obj.myVar = 20;
+  // obj.myFunc();
+
+  return 0;
+}
+```
+
+In this example:
+
+`BaseClass` includes a protected [variable](https://www.codecademy.com/resources/docs/cpp/variables) `myVar` and a protected [function](https://www.codecademy.com/resources/docs/cpp/functions) `myFunc()`, which `DerivedClass` can access and modify through inheritance.
+
+In the `main` function, `useProtectedMembers()` demonstrates accessing these members in a controlled manner.
+
+> **Note:** Attempts to access protected members directly from objects of `BaseClass` or `DerivedClass` result in compilation errors, maintaining encapsulation.