自定义拷贝构造函数

#include <iostream>
#include <string>
class String      
{  
	int length;
	char *str;
public:
	String(char*);
	String(const String &p);
	void Show()
	{
		cout<<str<<endl;
	}
};

String::String(char*s)
{
	if (s)
	{
		length=strlen(s);
		str=new char[length+1];
		strcy (str,s);
	}
	else
	{
		length=0;
		str=0;
	}

}

String::String(const String &p)
{
	length=p.length;
	str=new char[length+1];
	strcpy(str,p.str);
}

void main()
{
	String str1("Welcome to here!");
	String str2(str1);
	cout <<"str1: ";
	str1.show;
	cout<<"拷贝后\n str2: ";
	str2.show();
}