c++ declaring a struct code example

Example 1: constructor c++ struct

struct Rectangle {
    int width;  // member variable
    int height; // member variable

    // C++ constructors
    Rectangle()
    {
        width = 1;
        height = 1;
    }

    Rectangle( int width_  )
    {
        width = width_;
        height = width_ ;
    }

    Rectangle( int width_ , int height_ )
    {
        width = width_;
        height = height_;
    }
    // ...
};

Example 2: c++ struct

#include<iostream>
#include<string>
using namespace std;
struct student
{
  char name [20];
int age;
float marks;
};
int main()
{
student s;
cout<<"enter student name : "<<endl;
cin>>s.name;
cout<<"enter age : "<<endl;
cin>>s.age;
cout<<"enter marks : "<<endl;
cin>>s.marks;
cout<<"***********************"<<endl;
cout<<"name : "<<s.name<<endl;
cout<<"age : "<<s.age<<endl;
cout<<"marks : "<<s.marks<<endl;
return 0;
}