Store 2D array row in parallel array - c++

Question

I'm a beginner to C++, in my homework i have to save a row from a 2D array based on the inputted username and password. The saved row is to be a reference as to where the user info can be found in the 2D array. I haven't been able to figure out how to save the specific row to an integer. The whole code is displayed and the function to preform the task is called validateUser.
#include <iostream>
#include <string>
#include <fstream>
#include <sstream>
#include <iomanip>
using namespace std;
void showAll(string theAccounts[5][7]);
void sortInput(string theAccounts[5][7]);
bool validateUser(string theAccounts[5][7], string username, string password, int &saveRow);
bool readFile(string theAccounts[5][7]);
int main()
{
//Declare Necessary Variables and 2D array to store data from input file.
string username;
string password;
string accountData[5][7] = { " " };
bool userGood;
bool fileGood;
//Call the readFile function and capture the returned value.
fileGood = readFile(accountData);
//Test if file was successfully read, if so continue with program else exit with error message
if (fileGood == false)
{
cout << "Error occurred...File Unread...Program Exiting" << endl;
}
else
{
cout << "\nFile Read Successfully...\n\n" << endl;
//Ask user to Enter User Name or Zero to Exit
cout << "Enter the following information or 0 to Exit...\n";
cout << "Please Enter Your User Name > ";
//Read in User Name
//If User Name read in is “zero” Exit program.
cin >> username;
if (username == "0")
{
return 0;
}
//Ask the user to Enter Their Password or Zero to Exit
cout << "Please Enter Your User Password > ";
//Read in User Password
//If User Password read in is “zero” Exit program
cin >> password;
if (password == "0")
{
return 0;
}
//Call the Validate User function and capture the returned value
//If returned value from the Validate User function is TRUE continue program to check access code if U or A
//If U – code appropriately
//If A – code appropriately
//Else if returned value Not Valid from the Validate User function, FALSE, output message username and password invalid
}
return 0;
}
void showAll(string theAccounts[5][7])
{
const int Rows = 5;
const int Columns = 7;
ifstream accountFile;
accountFile.open("AccountData.txt");
if (accountFile.is_open())
{
for (int i = 0; i < Rows; i++)
{
for (int j = 0; j < Columns; j++)
{
cout << setw(8) << theAccounts[i][j];
}
cout << endl;
}
}
accountFile.close();
}
void sortInput(string theAccounts[5][7])
{
}
bool validateUser(string theAccounts[5][7], string username, string password, int &saveRow)
{
bool passed = false;
//test for username and password match whats stored in theAccounts
for (int i = 0; i < 5; i++)
{
if (username == theAccounts[i][0] && password == theAccounts[i][3])
{
saveRow = theAccounts[i];
}
}
return passed;
}
bool readFile(string theAccounts[5][7])
{
bool fileRead;
const int Height = 5;
const int Width = 7;
ifstream inputFile; //an ifstream object – input file stream object
inputFile.open("AccountData.txt"); // the open member function opens the text file and links it with
// inputFile to read data from the AccountData.txt file
//input validation to see if file opened
//if opened, read strings into theAccounts array - reset fileRead to true
if (inputFile.is_open())
{
fileRead = true;
for (int i = 0; i < Height; i++)
{
for (int j = 0; j < Width; j++)
{
inputFile >> theAccounts[i][j];
}
}
}
else
{
fileRead = false;
}
inputFile.close();
return fileRead;
}
The .txt file contains:
bham#gnet.com Blake Ham squid62 1987 U Teacher
jdark#att.net Jim Dark gymrat32 1985 A Master
hgreen#lakes.net Hannah Green flower22 2007 U Apprentice
tsmith#dna.com Tom Smith tuna20 2000 U Teacher
jarrow#pnet.com James Arrow ahoy10 2005 U Apprentice

Answer 1

I haven't been able to figure out how to save the specific row to an
integer
In OP function, the specific row is simply i, so all we have to do is to assign it to the variable passed by reference, saveRow and return.
I will not comment the general design of this program as I don't know how much of it is part of the assignment, so I'll use the same interface and data structures OP used:
bool validateUser(string theAccounts[5][7], string username, string password, int &saveRow)
{
//test for username and password match whats stored in theAccounts
for (int i = 0; i < 5; i++)
{
if (username == theAccounts[i][0] && password == theAccounts[i][3])
{
// match found, "save" the right row and return
saveRow = i;
return true;
}
}
// there's no match
return false;
}

Answer 2

For cleaner and easier approach, You should use a combination of std::map and std::vector. std::map<Key, Value> is a container where Keys are all unique and can be of any type you desire. Also Values can be any type you want but can be duplicated. So, imagine it as std::map<Deepblue, information> is an element, another element would be std::map<FirstStep, information> and so on. No two identical keys can be found. Therefore, the Key will be a string and the Information is going to be a vector<string> container of strings.
The below code works and it populates all your data from the input file to the map. Follow the comments and you should see how it works:
#include <iostream>
#include <map>
#include <vector>
#include <fstream>
#include <string>
#include <sstream>
int main()
{
std::map<std::string, std::vector<std::string>> MyMap; // map that has a string key and a vector of strings as information
std::ifstream InFile; // to read from a text file
InFile.open("C:\\....\\input.txt");
if (InFile.fail()) // terminate if failed
{
std::cout << "File did not open correctly!";
return 0;
}
std::string OneLine;
std::vector<std::string> MyVector;
std::string MyKey;
std::vector<std::string> MyValue;
while(std::getline(InFile, OneLine)) // while "reading a whole line" is valid
{
//split the whole line on whitespaces and convert it to a vector of strings
std::stringstream ss(OneLine);
std::string item;
while (getline(ss, item, ' '))
MyVector.push_back(item);
// Now take the first word and set it as the key because it is the email, so it is the "ID" of every line/person
MyKey = MyVector[0];
// Now take the rest of the vector as Value
for (int i = 1; i < MyVector.size(); i++)
MyValue.push_back(MyVector[i]);
// Now add this [Key, Value] pair to the map
MyMap[MyKey] = MyValue;
}
system("pause");
return 0;
}
Now hoover your mouse on this variable to see how it is structured. And do some research on how to access a map write/read etc.