cpp how to implement methods of a struct code example

Example 1: function in struct c++

struct foo {
  int bar;
  foo() : bar(3) {}   //look, a constructor
  int getBar() 
  { 
    return bar; 
  }
};

foo f;
int y = f.getBar(); // y is 3

Example 2: structs in c++

#include <bits/stdc++.h>
#include <iostream>

#define ll long long

using namespace std;

struct student{
	int roll;
	string name;
	int age;
	
	void studentDetails(){
		cout<<"Name is "<<name<<" Age is "<<age<<" roll no is "<<roll<<endl;
	}
};


int main(){
	
	student sumant;
	sumant.roll = 30;
	sumant.name = "Sumant Tirkey";
	sumant.age = 18;
	
	sumant.studentDetails();
	cout<<endl;

    return 0;
}