(C++) protected

Keyword indicating the level of class access.

The protected member variables and functions of a class can only be used from within a derived class. From outside the class, protected members are not accessable.

The code below shows class access:

class  Base
{
  public:
    int mBasePublic;
  protected:
    int mBaseProtected;
  private:
    int mBasePrivate;
};
//The class Derived inherits publicly from class Base
//In this example, however, the type of inheritance does not matter:
//Base's protected members get accessable in this class in all cases
class Derived : public Base 
{
  public:
    int mDerivedPublicPublic;
  protected:
    int mDerivedPublicProtected;
  private:
    int mDerivedPublicPrivate;
    void testBaseAccess() const
    {
      //BasePublic is accessable from inside any derived class
      this->mBasePublic;
      //BaseProtected gets accessable from inside any derived class
      this->mBaseProtected; 
    }
};

'protected' links

last edited (November 16, 2006) by bilderbikkel, Number of views: 6361, Current Rev: 7 (Diff)

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