Question

建立一个对象数组,内放5个学生的数据(学号,1门成绩).利用指针,统计平均成绩并输出第1,3,5个学生的数据.

#include <iostream>
using namespace std;
class Student
{
public:
Student(int,int);
int num;
int grade;
}
Student::Student(int n,int g)
{num=n;
grade=g;
}
int main()
{
Student a[5]={Student(1,50),Student(2,70),Student(3,88),Student(4,100),Student(5,72)};
int sum=0;
for(i=0;i<5;i++)
{int *p=&a[i].grade;
sum+=*p;
p++;
}
int average=sum/5;
cout<<"平均成绩是："<<average<<endl;
cout<<a[0].grade<<endl;
cout<<a[2].grade<<endl;
cout<<a[4].grade<<endl;
return 0;
}
我哪错了啊？

Answer 1

#include <iostream>
using namespace std;
class Student
{
      public:
             Student(int,int);
             int num;
             int grade; 
} ;//这里给你加了一个分号。
Student::Student(int n,int g)
{
        num=n;
        grade=g;
}
int main()
{
    Student a[5]={Student(1,50),Student(2,70),Student(3,88),Student(4,100),Student(5,72)};  
    int i,sum=0;//加了一个i的定义
    for(i=0;i<5;i++)
    {int *p=&a[i].grade;
       sum+=*p;
       p++;            
    }
    int average=sum/5;
    cout<<"平均成绩是："<<average<<endl;
    cout<<a[0].grade<<endl;
    cout<<a[2].grade<<endl;
    cout<<a[4].grade<<endl;
    return 0;
}

c++builder输出如下：