袁辉勇 4=25-1 构造函数 析构函数

    T (int xx) { x=xx; cout<<"construct: "<<x<<endl; }

using namespace std;

class T

{

int x;

public:

    T (int xx)

     { x=xx; cout<<"construct: "<<x<<endl; }

};

int main()

{

    T t(100);

    return 0;

}

~T () {cout<<"destruct: "<<x<<endl;}

#include <iostream>

using namespace std;

class T

{

    int x;

     public:

     T (int xx) { x=xx; cout<<"construct: "<<x<<endl; }

~T ( ) { cout<<"destruct: " <<x<<endl; }

};

int main(int argc, char *argv[])

{

    T t(100);

    return 0;

}

#include <iostream>

using namespace std;

class T

{

    int x;

    public:

    

    T (int xx){x=xx;  cout<<"construct: "<<x<<endl;}     

              

    ~T ()   {cout<<"destruct: "<<x<<endl;}           

};

int main(int argc, char *argv[])                  

{

    T t1(100),t2(999);

    cout<<"**********\n";

    return 0;

}

T t1(100);   T t2(999); cout<<"**********\n";

#include <iostream>

using namespace std;

class T

{

    int x;

    public:

    T (int xx){x=xx;  cout<<"construct: "<<x<<endl;}               

    ~T ()   {cout<<"destruct: "<<x<<endl;}           //（四） 

};

int main(int argc, char *argv[])                  

{

    T t1(100);

    T t2(999);

    cout<<"**********\n";

    return 0;

}

括号改变 执行顺序 T t1(100); { T t2(999); } cout<<"**********\n";

#include <iostream>

using namespace std;

class T

{

    int x;

    public:

    T (int xx){x=xx; cout<<"construct: "<<x<<endl;}

~T () {cout<<"destruct: "<<x<<endl;}

};

int main(int argc, char *argv[])

{

    T t1(100);

{ T t2(999);}

    cout<<"**********\n";

    return 0;

}