例: class a public A(int i, int Dfal=1; a2=j; cout<<As constructor called. n, cAOcout<<As destructor called. n') void printo(cout<< al=<<al <<end <<a2=<<a2 <<endl private int al a2 class b: public a public B(int i, int j, int k, int l, int m) BOcout<<B's destructor called n", void print((A printO; cout<<b1=<<bl<<endl; rivate int b1 a aa void mainO } B: B(int i, int j, int k, int I, int m): A(i, D), aa(k, D) B bb(1, 2, 3, 4, 5) b1=m bprin cout<<B' s constructor called \ n例：class A { public: A(int i, int j){a1=i; a2=j; cout<<“A’s constructor called.\n”;} ~A( ) {cout<<“A’s destructor called.\n”;} void print( ) {cout<<“a1=“<<a1 <<endl <<“a2=“<<a2<<endl;} private: int a1,a2; }; class B:public A { public: B(int i, int j, int k, int l, int m); ~B( ) {cout<<“B’s destructor called.\n”;} void print( ) {A::print(); cout<<“b1=“<<b1<<endl;} private: int b1; A aa; }; B::B(int i, int j, int k, int l, int m):A(i, j),aa(k, l) { b1=m; cout<<“B’s constructor called.\n”; } void main() { B bb(1,2,3,4,5); bb.print(); }