#include <iostream>
#include <string>
using namespace std;
class Student
{
private:
    int number;
    float score1,score2,score3;
    char *name;
public:
    Student();
    void get(int ,char *,float ,float ,float);
    float aver();
    void show();
    ~Student();
};

void Student::get(int numbers,char *names,float score1s,float score2s,float score3s)
{
    number=numbers;
    name=names;
    score1=score1s;
    score2=score2s;
    score3=score3s;
}

float Student::aver()
{
    return ((score1+score2+score3)/3);
}
void Student::show()
{
    cout<<"学号:"<<number<<"姓名:"<<name<<"语文:"<<score1<<"数学:"<<score2
        <<"英语:"<<score3<<"平均分:"<<aver()<<endl;
}
void main()
{
    int i,j;
    Student s[3];
    Student temp;
    s[0].get(1,"张三",90,88,89);
    s[1].get(2,"李四",99,90,95);
    s[2].get(3,"王五",78,80,69);
    for(i=0;i<3;i++)
        for(j=0;j<2;j++)
            if(s[j].aver()<s[j+1].aver())
            {temp=s[j];s[j]=s[j+1];s[j+1]=temp;}
    cout<<"按平均分从高到低排列"<<endl;
    s[0].show();
    s[1].show();
    s[2].show();
}
执行的时候出错`编译不出错``
Linking...
class.obj : error LNK2001: unresolved external symbol "public: __thiscall Student::Student(void)" (??0Student@@QAE@XZ)
class.obj : error LNK2001: unresolved external symbol "public: __thiscall Student::~Student(void)" (??1Student@@QAE@XZ)
Debug/class.exe : fatal error LNK1120: 2 unresolved externals
执行 link.exe 时出错.

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

为什么没人帮我解决吖?~

没看到构造函数和析构函数的定义

在类中只是 声明了构造和析构函数 并没有 在类外定义
可以在 类内 定义
Student(){}和~Student(){}

#include <iostream>
#include <string>
using namespace std;
class Student
{
private:
    int number;
    float score1,score2,score3;
    char *name;
public:
    Student();
    void get(int ,char *,float ,float ,float);
    float aver();
    void show();
    ~Student();
};

void Student::get(int numbers,char *names,float score1s,float score2s,float score3s)
{
    number=numbers;
    name=names;
    score1=score1s;
    score2=score2s;
    score3=score3s;
}

float Student::aver()
{
    return ((score1+score2+score3)/3);
}
void Student::show()
{
    cout<<"学号:"<<number<<"姓名:"<<name<<"语文:"<<score1<<"数学:"<<score2
        <<"英语:"<<score3<<"平均分:"<<aver()<<endl;
}
Student::Student(){}//构造函数的定义
Student::~Student(){}//析构函数的定义，要知道只有函数声明是不行的
void main()
{
    int i,j;
    Student s[3];
    Student temp;
    s[0].get(1,"张三",90,88,89);
    s[1].get(2,"李四",99,90,95);
    s[2].get(3,"王五",78,80,69);
    for(i=0;i<3;i++)
        for(j=0;j<2;j++)
            if(s[j].aver()<s[j+1].aver())
            {temp=s[j];s[j]=s[j+1];s[j+1]=temp;}
    cout<<"按平均分从高到低排列"<<endl;
    s[0].show();
    s[1].show();
    s[2].show();
}

谢谢``

还有，你的冒泡排序有一处也是不准确的，虽然运算正确但计算次数多了：你可以试一下
for(i=0;i<3;i++)//此处应该为for(i = 0; i < 2; i++)
        for(j=0;j<2;j++)
            if(s[j].aver()<s[j+1].aver())
            {temp=s[j];s[j]=s[j+1];s[j+1]=temp;}