才开始学呢，大侠们帮帮我啊！
//student.h
#ifndef STUDENT_h
#define STUDEN_h
class Student
{
public:
    void input(char* n,char *na,float s);
    void modify(float s);
    void display();
private:
    float score;
    char* name;
    char* id;
};
#endif
//student.cpp
#include<iostream.h>
#include<string.h>
#include "Student.h"
void Student::input(char* n,char* na,float s)
{
    score=s;
    id=new char[strlen(n)+1];
    strcpy(id,n);
    name=new char[strlen(na)+1];
    strcpy(name,na);
}
void Student::modify (float s)
{
    score=s;
}
void Student::display ()
{
    cout << "\n id:" << id;
    cout << "\n name:" << name;
    cout << "\n score:" << score;
}

--------------------Configuration: 2 - Win32 Debug--------------------
Compiling...
student.cpp
Linking...
LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/2.exe : fatal error LNK1120: 1 unresolved externals
执行 link.exe 时出错.

2.exe - 1 error(s), 0 warning(s)

谢谢啊！
才开始学，还以以只要定义了类，有了类的实现就可以编译呢，忘记了连main函数都没写
。。。。。

唉，这种错误我也犯过呢