程序基石系列之自动调用析函数

当对象超了它的作用域时，编译器将自动调用析函数。即在对象的定义点处构造函数被调用，但析函数调用的惟一证据是包含此对象的右括号。

/*
 *  Constructors &Destructors
 *  Eclispe CDT
 */
#include <iostream>
using namespace std;

class Tree{
	int height;
public:
	Tree(int initialHeight);//Constructor
	~Tree();//Destructor
	void grow(int years);
	void printsize();
};

Tree::Tree(int initialHeight){
	height = initialHeight;
	//cout<<"Initial Height:"<<height<<endl;
}

Tree::~Tree(){
	cout<<"inside Tress destructor"<<endl;
	printsize();
}

void Tree::grow(int years){
	height +=years;
}

void Tree::printsize(){
	cout<<"Tree height is "<<height<<endl;
}

int main(){
	cout<<"before opening brace"<<endl;
	{
		Tree t(12);
		cout<<"after Tress creation"<<endl;
		t.printsize();
		t.grow(4);
		cout<<"before closing brace"<<endl;
	}
	cout<<"after closing brace"<<endl;
}

程序输出结果：

before opening brace
after Tress creation
Tree height is 12
before closing brace
inside Tress destructor
Tree height is 16
after closing brace

可以看到析函数在包括它的右括号处被调用。

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