shiti2_5_1.cpp

为初学者提供的最佳的C++程序设计源程序库

#include<iostream.h>
#include<string.h>
class String
{
public:
	String(int size=80)
	{
		length=size;
		buf=new char[length+1];
		*buf='\0';
	}
	String(char *s)
	{
		length=strlen(s);
		buf=new char[length+1];
		strcpy(buf,s);
	}
	String(const String&str)
	{
		length=strlen(str.buf);
		buf=new char[length+1];
		strcpy(buf,str.buf);
	}
	~String(){delete[]buf;}
	String&operator=(const String&str)
	{
		length=str.length;
		strcpy(buf,str.buf);
		return *this;
	}
	void Print(){cout<<buf<<endl;}
	friend String operator+(const String&str1,const String&str2)
	{
		String temp(strlen(str1.buf)+strlen(str2.buf)+1);
		strcpy(temp.buf,str1.buf);
		strcat(temp.buf,str2.buf);
		return temp;
	}
private:
	char *buf;
	int length;
};
void main()
{
	String str1,str2("Hello,"),str3("everyone!");
	str1=str2+str3;
	str1.Print();
}