How to read first and last name with void function - c++

Question

I can easily create a void function to output something like a header, but I cannot get a program to read a user's input and then output it to them.
ie. Have a program say "Please enter your first name" and then output "You entered: (what they put)"
An example of what I have:
#include<iostream>
#include<conio.h>
#include<iomanip>
#include<fstream>
using namespace std;
void namefn()//namefn prototype
int main(){
string firstName,lastName;
return 0;
}
void namefn(string firstName, string lastName){
cout<<"please enter your first and last name "<<endl;
}

Answer 1

Use cin to read, is in iostream.
i.e.
cin >> firstName;

Answer 2

cout << "enter your first and last name:";
cin >> firstName >> lastName;
cout << firstName << " " << lastName;
if you want the program to display the first name and last name separately then this:
cout << "enter you first name:";
cin >> firstName;
cout << firstName << endl;
cout << "Enter your last name:";
cin >> lastName;
cout << lastName << endl;

Answer 3

Try this:
#include <iostream>
#include <string>
void displayFirstAndLast(const std::string& firstName, const std::string& lastName)
{
std::cout << "You are " << firstName << " " << lastName << std::endl;
}
int main(){
std::string firstName;
std::string lastName;
std::cout << "Please enter your first and last name " << std::endl;
std::cin >> firstName >> lastName;
displayFirstAndLast(firstName, lastName);
return 0;
}
I think, that you want something like this.
Or with something like "header"
#include <iostream>
#include <string>
void displayFirstAndLast(const std::string& firstName, const std::string& lastName);
int main(){
std::string firstName;
std::string lastName;
std::cout << "Please enter your first and last name " << std::endl;
std::cin >> firstName >> lastName;
displayFirstAndLast(firstName, lastName);
return 0;
}
void displayFirstAndLast(const std::string& firstName, const std::string& lastName)
{
std::cout << "You are " << firstName << " " << lastName << std::endl;
}