何時執行建構函式和析造函數

局部對象的建構函式在遇到對象說明語句時執行
全域對象的建構函式在main()開始執行之前執行

#include <iostream.h>

class myclass

{

public:

       int who;

       myclass(int id);

       ~myclass();

};

myclass::myclass(int id)

{

       cout<<"Initializing"<<id<<endl;

       who=id;

}

myclass::~myclass()

{

       cout<<"Destructing"<<who<<endl;

}

 

myclass global_ob1(1),global_ob2(2);

void main()

{

       myclass local_ob1(3);

       cout<<"This will not be first line displayed"<<endl;

       myclass local_ob2(4);

}

 運行結果如下：

Initializing1
Initializing2
Initializing3
This will not be first line displayed
Initializing4
Destructing4
Destructing3
Destructing2
Destructing1