No Output and Randomising String Array - c++

Question

my assignment asks me to open a text file and output a random array and loop it back to the question. I am wondering as why my code has no output? I appreciate all the help I get. Thank you very much.
#include <iostream>
#include <cstdlib>
#include <string>
#include <fstream>
#include <ctime>
using namespace std;
int main()
{
srand(time(0));
ifstream fin;
fin.open("songs.txt");
if (!fin.good()) throw "I/O error";
string ans;
const int MAX_SONGS = 200;
int nSongs=0;
string song[MAX_SONGS];
while (fin.good())
{
// read txt file
string aSong;
getline(cin, aSong);
// add song if still have space
if (nSongs < MAX_SONGS)
song[nSongs++] = aSong;
}
fin.close();
cout<<"hi!";
for (int i=0; i<nSongs; i++)
{
song[i] = (rand() % nSongs);
cout << " play a song [Y/N]? ";
getline(cin, ans);
if (ans=="Y"||ans=="y")
cout << song[i]<<endl;
break;
if (ans=="n"||ans=="N")
break;
}
}

Answer 1

When you read in the file, you are using cin instead of fin so you end up reading from the keyboard instead.
getline(cin, aSong); // getline(fin,aSong)
Normally if the file is just a regular text file with newlines you write it more compact
string aSong;
while ( fin >> aSong )
{
if (nSongs < MAX_SONGS)
song[nSongs++] = aSong;
}
This form
while (fin.good())
is wrong, because the bit indicating error is set after you do getline but you still continue after getline failed.
if (nSongs < MAX_SONGS)
song[nSongs++] = aSong;
When you open the file, use the following syntax instead
ifstream fin("songs.txt");
if (fin)
{
...
}
or if you want to keep they way you had it
if (!fin)
{
throw "I/O error";
}
EDIT:
song[i] = (rand() % nSongs);
should be
int j = (rand() % nSongs);
...
if (ans == "Y" || ans == "y")
{
cout << song[j] << endl;
if you wanted to show a random song.