若有以下程序： #include〈iostream〉 using namespace std; class Base { public: Base ( ) { x=0; } int x; }; class Derived1 : virtual public Base { public: Derived1() { x=10; } }; class Derived2 : virtual public Base { public: Derived2() { x=20; } }; class Derived : public Derived1,protected Derived2 { }; int main() { Derived obj; cout〈〈obj.x〈〈end1; return 0; } 该程序运行后的输出结果是〈u〉 【15】 〈/u〉。
