Différence entre héritage privé, public et protégé

Question

J'ai cherché dans SO et je n'ai pas trouvé de bonne description concernant la différence entre public , private et protected L'héritage en C++. Toutes les questions supposaient un cas spécifique. Quelle est la différence ?

Answer 1

Eh bien, je pense ce décrit assez bien les concepts pertinents.

Answer 2

Voir ces codes pour comprendre les caractéristiques du c++ sur l'héritage... J'ai mis le résultat à la fin... J'espère que cela vous aidera.

#include <iostream>
using namespace std;

class A {
private:
    void pri();
    A(int a);
protected:
    virtual void pro() {}
public:
    void pub1() { cout<<"A.pub1()\n"; }
    virtual void pub2() { cout<<"A.pub2()\n"; }
    virtual void pub3() { cout<<"A.pub3()\n"; }
    virtual void pub4() { cout<<"A.pub4()\n"; }
    virtual void pub5() { cout<<"A.pub5()\n"; }
    virtual void pub6() { cout<<"A.pub6()\n"; }
    virtual void pub7() { cout<<"A.pub7()\n"; }
    virtual void pub8() { cout<<"A.pub8()\n"; }
    void pub9() { cout<<"A.pub9()\n"; }
    virtual void pub10() { cout<<"A.pub10()\n"; }
    void pub11() { cout<<"A.pub11()\n"; }
    explicit A() {}
    virtual ~A() {}
};

class B : public A {
private:
    void pri() { cout<<"B.pri()\n"; }
protected:
    virtual void pub4() { cout<<"B.pub4()\n"; }
    void pub6() { cout<<"B.pub6()\n"; }
public:
    void pro() { cout<<"B.pro() "; B::pri(); }
    void pub1() { cout<<"B.pub1()\n"; }
    void pub2() { cout<<"B.pub2()\n"; }
    void pub5() { cout<<"B.pub5()\n"; }
    virtual void pub7() { cout<<"B.pub7()\n"; }
    virtual void pub8() { cout<<"B.pub8()\n"; }
    virtual void pub9() { cout<<"B.pub9()\n"; }
    void pub10() { cout<<"B.pub10()\n"; }
    void pub11() { cout<<"B.pub11()\n"; }
    explicit B() {}
};

class C : protected B {
public:
    void pub4_() { cout<<"C.pub4_() "; B::pub4(); }
    virtual void pub5() { cout<<"C.pub5()\n"; }
};

class D : private B {
public:
    void pub4_() { cout<<"D.pub4_() "; B::pub4(); }
};

class E : public B {
public:
    virtual void pub4() { cout<<"E.pub4()\n"; }
    virtual void pub7() { cout<<"E.pub7()\n"; }
    virtual void pub8() { cout<<"E.pub8()\n"; }
    virtual void pub9() { cout<<"E.pub9()\n"; }
    virtual void pub10() { cout<<"E.pub10()\n"; }
    virtual void pub11() { cout<<"E.pub11()\n"; }
};

void testClasses() {
    A* ap=new B();
    ap->pub1(); // == A::pub1() //important
    // (new B()).pub1() can't override non-virtual A::pub1() for an A* pointer.
    ap->pub2(); // == B::pub2() //important
    // (new B()).pub1() can override virtual A::pub1() for an A* pointer.
    B b;
    b.A::pub1();
    b.pro();
    B* bp=new B;
    bp->pub3();
    C c;
    //c.pub3(); //error
    //c.pub4(); //error
    c.pub4_();
    c.pub5();
    D d;
    //d.pub3(); //error
    //d.pub4(); //error
    d.pub4_();
    E e;
    //e.pub4(); //error
    delete ap;
    ap = new E();
    ap->pub4();
    ap->pub5();
    ap->pub6();
    ap->pub7();
    delete bp;
    bp = new E();
    e.pub8();
    e.A::pub8();
    e.B::A::pub8();
    e.B::pub8();
    ap->pub8();
    bp->pub8();
    e.pub9();
    e.A::pub9();
    e.B::A::pub9();
    e.B::pub9();
    ap->pub9(); // important
    bp->pub9();
    e.pub10();
    e.A::pub10();
    e.B::A::pub10();
    e.B::pub10();
    ap->pub10(); // important
    bp->pub10(); // very important... eventhough B::pub10() is non-virtual,
                 // bp->pub10() != b.pub10();
    e.pub11();
    e.A::pub11();
    e.B::A::pub11();
    e.B::pub11();
    ap->pub11();
    bp->pub11();
    delete ap;
    delete bp;
    return;
}

int main() {
    testClasses();
    return 0;
}

/////////////////////////////////////////
........
Result :
........

A.pub1()
B.pub2()
A.pub1()
B.pro() B.pri()
A.pub3()
C.pub4_() B.pub4()
C.pub5()
D.pub4_() B.pub4()
E.pub4()
B.pub5()
B.pub6()
E.pub7()
E.pub8()
A.pub8()
A.pub8()
B.pub8()
E.pub8()
E.pub8()
E.pub9()
A.pub9()
A.pub9()
B.pub9()
A.pub9()
E.pub9()
E.pub10()
A.pub10()
A.pub10()
B.pub10()
E.pub10()
E.pub10()
E.pub11()
A.pub11()
A.pub11()
B.pub11()
A.pub11()
B.pub11()