using while loop to create objects [closed] - c++

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The biggest issue I am dealing with is in my main.cpp file however I posted my video.h file and video.cpp file just in case.
I am having a difficult time understanding the concept of reading input and then creating an object.
I have a class Video that contains the member functions needed to create an object. My class works fine . In my main I want to be able to read the input before I create the object rather than creating an object then initializing the variables.
video.h
#ifndef VIDEO_H
#define VIDEO_H
#include<iostream>
#include<string>
using namespace std;
class Video{
public:
// constructor works fine
Video(string name, string link, string comment,
double rating, int stars);
void print();
// member variables
private:
string m_name;
string m_link;
string m_comment;
double m_rating;
int m_stars;
};
#endif
video.cpp
#include<iostream>
#include "video.h"
using namespace std;
Video :: Video (string name, string link, string comment,
double rating, int stars){
m_name = name;
m_link = link;
m_comment = comment;
m_rating = rating;
m_stars = stars;
}
void Video :: print (){
cout << m_name << ", " << m_link << ", " << m_comment << ", " <<
m_rating << ", ";
for(int count = 0; count < m_stars; ++count){
cout << "*";
//cout << endl;
}
cout << endl;
//<< " , " << m_stars << endl;
}
main.cpp
#include <iostream>
#include <string>
using namespace std;
#include "video.h"
int main()
/* My program can create objects and initialize the string variables
if the data is hard-coded when the object is created however I want
read data using cin and a while loop then create an object.
Video video1("Title One", "www.youtube.com/one",
"Comment ONE", 1.1, 1);
Video video2("Title Two", "www.youtube.com/two",
"Comment TWO", 2.2, 2);
video1.print();
video2.print();
*/
{
while (Video >> cin) { //I want to use a while loop here
/* The program needs to read these getlines
and other variables in order to store names or comments
that have spaces */
getline(cin, name); // user enters the name then presses "enter"
getline(cin, link); // user enters the link then presses "enter"
getline(cin, comment); // user enters the comment then presses "enter"
double rating; // user enters the rating then presses "enter"
int stars; // user enters the amount of stars then presses "enter"
Video video_one; /* Once the user enters data for all five members a new object is created */
}
}

Answer 1

I would just do
while(true)
{
getline(cin, name); // user enters the name then presses "enter"
getline(cin, link); // user enters the link then presses "enter"
getline(cin, comment); // user enters the comment then presses "enter"
double rating; // user enters the rating then presses "enter"
cin >> rating;
int stars; // user enters the amount of stars then presses "enter"
cin >> stars;
Video video_one(name,link,comment,rating,stars); /* Once the user enters data for all five members a new object is created */
}

Answer 2

Note:
you can't do this:
while(video>>cin){...}
there is no friend function overloading extraction >> operator. to do What you want to do, overload the extraction operator (>>) inside your Video class :
friend istream &operator>>(istream &input, Video &V)
{
input>> V.m_name>>V.m_link>>V.m_comment...;
return input;
}
and use it like this:
while(cin>>video){...}
Also to read input first then instantiate object,you need a container (a vector or an array) to hold all the new video objects that gets created. Do you know the number of videos that will be entered beforehand? The reason is because arrays are assigned a fixed amount of memory and if the combined amount of new video objects' data entered exceeds the amount of array's memory, it will lead to segmentation fault. There are ways to make your array dynamic but its much easier to use a Vector class since it will automatically increase the container size(get itself more memory) as more video titles are entered. I used a vector called listofVideos. At the end of the while loop you use an iterator to traverse through the vector.
#include <iostream>
#include <string>
#include <vector>
#include <sstream>
using namespace std;
typedef struct Video_t{ //I used a struct in this case instead of the class
string m_name;
string m_link;
string m_comment;
int m_stars;
}Video_t;
//#include "video.h"
int main()
{
string buffer;
string name;
string link;
string comment;
double rating;
double stars;
vector<Video_t> listofVideos; //I used a vector in this case to store all the videos.
while (getline(cin,buffer)&&buffer != "end") { //I used a control word to signal end of inputs.
if(buffer.empty());
istringstream is(buffer);
if(is>>name>>link>>comment>>stars)
{
Video_t vid;
vid.m_name = name;
vid.m_link=link;
vid.m_comment = comment;
vid.m_stars = stars;
listofVideos.push_back(vid);
}
}
vector<Video_t>::iterator it;
for(it=listofVideos.begin();it!=listofVideos.end();++it)
cout<<(*it).m_name<<" "<<(*it).m_link<<" "<<(*it).m_stars<<endl;
return 0;
}