为什么即使在我尝试声明它之后，我的代码仍然说它具有不完整的类型？

Question

I am writing a program that displays a number of students test scores in the form of a table and then calculates and displays the average. Upon running the code, I get the following errors(also pictured below): variable has incomplete type 'struct students' struct students st[50]; ^ note: forward declaration of 'students' struct students st[50];

I have declared students and have tried declaring st and I am just not sure what the problem is. Below is a typed version and a screenshot of my code:

#include <iostream>
using namespace std;
int Main()
{
  int students;

   struct students st[50]; 
   return 0;
}

Code errors Picture of typed code

Answer 1

The structure students used in this declaration

struct students st[50];

is not defined yet. So the compiler issues an error because you may not declare an array with an incomplete element type.

Answer 2

You have to define it first. You can also use this style.

struct student{
    ...
};

int main{
    student* st[50];
    for(int i=0; i<50;i++)
        st[i]=new student;
    return 0;
}