4-9-0.txt

来自「思路很清晰的c++课件。例子很简明」· 文本 代码 · 共 30 行

基类的构造函数带参数,派生类必须定义构造函数,目的是向基类的构造函数传递参数

#include <iostream.h>

class base{
	int i;
public:
	base(int n)
	{	cout<<"Construction base class\n";
		i=n;
	}
	void showi(){cout<<i<<"\n";}
};

class derived:public base{
	int j;
public:
	derived(int n):base(n)
	{	cout<<"Constructing derived class\n";
		j=0;
	}
	void showj(){cout<<j<<"\n";}
};

void main()
{	derived x(10);
	x.showi();   
	x.showj();
}