下面程序的运行结果是: #include <iostream> using namespace std; class BaseClass { public: ~BaseClass(){cout<<"~BaseClass() is called!"<<endl;} }; class DerivedClass:public BaseClass { public: ~DerivedClass(){cout<<"~DerivedClass() is called!"<<endl;} }; int main() { DerivedClass d; return 0; }
时间: 2024-03-24 15:39:19 浏览: 19
下面是程序的输出结果:
```
~DerivedClass() is called!
~BaseClass() is called!
```
程序中,类DerivedClass是公共继承自BaseClass的派生类。在main函数中,声明了一个DerivedClass对象d。当程序运行结束时,程序会自动调用d的析构函数,并按照继承顺序先调用DerivedClass的析构函数,再调用BaseClass的析构函数。因此,输出结果为~DerivedClass() is called!和~BaseClass() is called!。
相关问题
#include<iostream> using namespace std class Base{ protected: Base(){cout<<'A';} Base(charc){cout<<c;}}; class Derived:public Base{ public: Derived(char c){cout<<c;}}; int main() {Derived dl('B'); return 0;} 执行这个程序屏幕上将显示输出
程序中存在语法错误,正确的代码应该是这样的:
```
#include<iostream>
using namespace std;
class Base {
protected:
Base() {
cout << 'A';
}
Base(char c) {
cout << c;
}
};
class Derived : public Base {
public:
Derived(char c) : Base(c) {
cout << c;
}
};
int main() {
Derived dl('B');
return 0;
}
```
运行结果是:`AB`。因为在创建 Derived 对象时会先调用 Base 的构造函数,然后再调用 Derived 的构造函数。在 Base 的默认构造函数中输出了字符 A,在 Base 的带参构造函数和 Derived 的构造函数中输出了字符 B。所以最终输出的结果是 AB。
#include<iostream> using namespace std; class Base public: virtual void Show( )cout<<'B';; ,; class Derived:public Base 1 public: void Show( ) cout< <'D';- ,; int main( ) 1 Base *pl=new Derived; Derived *p2=new Derived; p1->Show0; p2->Show0; delete p1; delete p2; return 0; } 运行这个程序的输出结果是_
这个程序存在语法错误,无法通过编译。具体地说,class Base的定义缺少了一个左花括号,应该修改为class Base{。同时,class Derived的定义也缺少了一个左花括号,应该修改为class Derived:public Base{。修改后的程序如下:
```c++
#include<iostream>
using namespace std;
class Base {
public:
virtual void Show() {
cout << 'B';
}
};
class Derived:public Base {
public:
void Show() {
cout << 'D';
}
};
int main() {
Base *p1 = new Derived;
Derived *p2 = new Derived;
p1->Show();
p2->Show();
delete p1;
delete p2;
return 0;
}
```
运行这个程序的输出结果是:
```
D
D
```