Search for objects within a vector - c++

Question

I am trying to find a way, within my code to search for an object that is in the Vectors that I have used. I am already pushing back the information into the different vectors and I know about .size to display the info. I want the user to be able to enter the bank account number then if that is correct display the contents of the other vectors.
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;
//declaring four vectors
std::vector<string>names;
std::vector<string>address;
std::vector<int>age;
std::vector<double>accountnumber;
//forward declaration of functions
void namesInput ();
void addressInput ();
void ageInput ();
void accountnumberInput ();
int main()
{
//variable for switch statement
int choice;
system("title HSBC Online Banking");
system("color B6");
cout << "Please select from the following options" << endl;
cout << "----------------------------------------" << endl;
cout << "1. Enter profile " << endl;
cout << "2. Search for client " << endl;
cout << "3. Exit" << endl;
cin >> choice;
switch(choice)
{
case 1:
//calling functions for first switch case
namesInput ();
addressInput ();
ageInput ();
accountnumberInput ();
system("cls");
break;
case 2:
break;
case 3:
system("exit");
break;
}
return 0;
}
void namesInput ()
{
system("cls");
for (int i = 1; i <= 3; i++)
{
string temp;//variable to give to vector
cout<<"Enter " << i << " first, middle and last names : ";
cin>>temp;
names.push_back(temp);//push back into vector
}
}
void addressInput ()
{
system ("cls");
for (int i = 1; i <= 3; i++)
{
string temp;//variable to give to vector
cout<<"Enter " << i << " House Number, Street, Postcode : ";
cin>>temp;
address.push_back(temp);//push back into vector
}
}
void ageInput ()
{
system ("cls");
for (int i = 1; i <= 3; i++)
{
int temp;//variable to give to vector
cout<<"Enter " << i << " Day, Month, Year : ";
cin>>temp;
age.push_back(temp);//push back into vector
}
}
void accountnumberInput ()
{
system ("cls");
for (int i = 1; i <= 1; i++)
{
int temp;//variable to give to vector
cout<<"Enter " << i << " Account Number ";
cin>>temp;
accountnumber.push_back(temp);//push back into vector
}
main ();
}
void findClient ()
{
cout << "To find a client please enter their account number" << endl;
}

Answer 1

std::vector<double>accountnumber;
Using a double for account numbers does not seem a good choice to me: you may want to use a std::string instead.
For example: note that "exact" comparison between doubles is not possible (so searching for account numbers using doubles as keys is problematic); instead you can do that with strings.
So, assuming you use a vector<string> for account numbers, you can use std::find() to find a given account position in the vector, e.g.:
auto it = find(accountNumbers.begin(), accountNumbers.end(),
accountNumberToFind);
if (it != accountNumbers.end())
{
... Found, process it ...
}
Once you have the iterator to the found account, you can get the vector 0-based index from it using a simple pointer/iterator arithmetic like (it - accountNumbers.begin()).
Then, given this index, you can access the corresponding items in the other vectors.
However, from an object-oriented design perspective, I'd prefer defining a class for accounts, with several fields like account number, name, address, etc., and have a single vector<Account> (instead of several vectors of single account attributes).

Answer 2

There are some parts of your code that I'd suggest to revisit, however, according to you code, you can just do the following:
void lookForAccount(){
system ("cls");
for (int i = 1; i <= 1; i++)
{
int temp;//variable to give to vector
cout<<"Enter " << i << " Account Number you want to look for";
cin>>temp;
for(int j = 0;j<accountnumber.size();j++){
if(accountnumber[j]==temp){
cout<<"account number: "<<accountnumber[j]<<", name: "<<names[j]<<"etc..."<<endl;
}
}
}
main ();
}
Instead of this dummy method I'd anyway suggest to use iterators and std::find.
However, as pointed out in comments, this code is bug prone due to several reasons: handling account number by double is not the best choiche. Furthermore, I'd suggest to redesign your code to handle all the account information using a C++ objects.