Search Function returns wrong results - c++11

Question

I have made a function for my program that reads from a text file, adds content to a vector and then search in that vector. The Problem is that even if the file is empty it shows that it found something, on the other side if i change return value to 0 it does not give results at all!
#include <iostream>
#include <string>
#include <vector>
#include <fstream>
#include <algorithm>
using namespace std;
vector<string> contacts;
//This function returns at what index the name is found
int searchContact(string contactToSearch)
{
string entry;
ifstream input;
input.open("contacts.txt");
while (input.good())
{
while (getline(input, entry))
{
contacts.push_back(entry);
}
input.close();
}
for(int i = 0; i < contacts.size(); i++)
{
if(contactToSearch == contacts[i])
{
//Found => Returning index rest of program can see index
return i;
}
}
return 1;
}

Answer 1

I have just refactored your code a little. Further improvements are possible, but to begin with
1) You dont need a while for input.good()
2) You were trying to return 0 and 1 which are indeed valid positions where the string could have been present in the vector
All these aside, I still think your code might not properly populated the array The reasons for this maybe :- case sensitive comparison, reading incorrect file, binary file.. etc..
Here is a refactored code that you could use
#include <iostream>
#include <string>
#include <vector>
#include <fstream>
#include <algorithm>
using namespace std;
void readContacts(const string &fileName inputFileName, vector<string> &contacts){
string entry;
ifstream input;
input.open(inputFileName);
if (input.good())
{
while (getline(input, entry))
contacts.push_back(entry);
input.close();
}
}
int searchContact(const string &contactToSearch, vector<string> &contacts)
{
for (int i = 0; i < contacts.size(); i++)
{
if (contactToSearch == contacts[i])
return i;
}
return -1;
}
int main(){
vector<string> contacts;
// This needs to be filled in with the contact name u want to search
string contactToSearch;
readContacts("contacts.txt", contacts);
int index = searchContact(contactToSearch, contacts)
if (index != -1)
cout << "Found Contact " << contactToSearch" at location " << index << endl;
else
cout << "Could Not find contact " << contactToSearch << endl;
}