不明确符号
#include<stdafx.h>
#include<iostream>
using namespace std;
#include<string.h>
class string{
public:
string(int size=80);
string(char *s);
string(string &s);
~string(){
delete sptr;
}
int getlength(){
return length;
}
void print(){
cout<<sptr<<endl;
}
private:
int length;
char *sptr;
};
string::string(int size){
length=size;
sptr=new char[length+1];
*sptr='\0';
}
string::string(char *s){
length=strlen(s);
sptr=new char[length+1];
strcpy(sptr,s);
}
string::string(string &s){
length=s.length;
sptr=new char[length+1];
strcpy(sptr,s.sptr);
}
void main(){
string s1,s2("This is a string.");
cout<<s1.getlength()<<endl;
s2.print();
char *str1="That is a program.";
string s3(str1);
s3.print();
string s4(s2);
s4.print();
}
《C++语言程序设计》吕风xi版例11.1在vs2008team版编译
编译出现:error C2872: “string”: 不明确的符号
请问应如何解决?