第六周 课后实践：阅读程序

（4）问题及代码：

#include <iostream>using namespace std;class example{public:    example()    {        cout<<"Default Constructing! "<<endl;    }    example(int n)    {        i=n;        cout<<"Constructing: "<<i<<endl;    }    ~example()    {        cout <<"Destructing: "<<i<<endl;    }    int get_i()    {        return i;    }private:    int i;};int sqr_it(example o){    return o.get_i()* o.get_i();}int main(){    example x(10);    cout<<x.get_i()<<endl;    cout<<sqr_it(x)<<endl;    return 0;}

 

运行结果：

 

 

（5）问题及代码：

#include <iostream>using namespace std;class AA{public:    AA(int i,int j)    {        A=i;        B=j;        cout<<"Constructor\n";    }    AA(AA &obj)    {        A=obj.A+1;        B=obj.B+2;        cout<<"Copy_Constructor\n";    }    ~AA()    {        cout<<"Destructor\n";    }    void print()    {        cout<<"A="<<A<<",B="<<B<<endl;    }private:    int A,B;};int main(){    AA a1(2,3);    AA a2(a1);    a2.print();    AA *pa=new AA(5,6);    pa->print();    delete pa;    return 0;}

 

运行结果：