C++ reading file search for something in that file - c++

Question

So I have a .txt file looking like this:
1:Meat Dish:Steak:11.5
2:Fish Dish:Fish and chips:12
The first number is the itemNo, 'Meat Dish' is my category, 'Steak' is my description and finally '11.5' is my price.
So basically I want to search for the itemNo and I want it to display the price from that line. This is what I have until now:
#include <iostream>
#include <fstream>
#include <string>
#include <vector> // We will use this to store Players
using std::string;
using std::ofstream;
using std::ifstream;
using std::cout;
using std::cin;
struct MenuList // Define a "Player" data structure
{
string itemNo;
string category;
string descript;
double price;
};
std::istream& operator>>(std::istream& infile, MenuList& menu)
{
// In this function we will define how information is inputted into the player struct
// std::cin is derived from the istream class
getline(infile, menu.itemNo, ':');
getline(infile, menu.category, ':');
getline(infile, menu.descript, ':');
infile >> menu.price;
// When we have extracted all of our information, return the stream
return infile;
}
std::ostream& operator<<(std::ostream& os, MenuList& menu)
{
// Just like the istream, we define how a player struct is displayed when using std::cout
os << "" << menu.itemNo << " " << menu.category << " - " << menu.descript;
// When we have extracted all of our information, return the stream
return os;
}
void Load(std::vector<MenuList>& r, string filename)
{
std::ifstream ifs(filename.c_str()); // Open the file name
if(ifs)
{
while(ifs.good()) // While contents are left to be extracted
{
MenuList temp;
ifs >> temp; // Extract record into a temp object
r.push_back(temp); // Copy it to the record database
}
cout << "Read " << r.size() << " records.\n\n";
}
else
{
cout << "Could not open file.\n\n";
}
}
void Read(std::vector<MenuList>& r) // Read record contents
{
for(unsigned int i = 0; i < r.size(); i++)
cout << r[i] << "\n";
}
void Search(std::vector<MenuList>& r) // Search records for name
{
string n;
cout << "Search for: ";
cin >> n;
for(int i = 0; i < r.size(); i++)
{
if(r[i].itemNo.find(n) != string::npos)
cout << r[i];
}
}
int main()
{
std::vector<MenuList> records;
Load(records, "delete.txt");
Read(records);
Search(records);
return 0;
}
I don't really know how to make it so it shows just the price without showing the whole line.

Answer 1

I have written my own code that reads in your text file and stores the information in a struct. Once you have a vector of MenuList, it is dead simple to only print what you want.
include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
using namespace std;
struct MenuList // Define a "Player" data structure
{
string itemNo;
string category;
string descript;
double price;
};
void addToList(vector<MenuList*>& vector_menu_list, string& itemNo, string& category, string& descript, string& price)
{
MenuList* p_menu_list = new MenuList;
p_menu_list->itemNo = itemNo;
p_menu_list->category = category;
p_menu_list->descript = descript;
p_menu_list->price = std::stod(price);
vector_menu_list.push_back(p_menu_list);
}
vector<MenuList*> readFile(string filename, bool& error_encountered)
{
vector<MenuList*> vector_menu_list;
ifstream file;
file.open(filename);
if (file.is_open())
{
string itemNo;
string category;
string descript;
string price;
short number_of_colons_encountered = 0;
char c;
while (file.get(c))
{
if ('\n' != c && EOF != c)
{
if (':' == c)
{
number_of_colons_encountered++;
continue;
}
switch (number_of_colons_encountered)
{
case 0:
itemNo += c;
break;
case 1:
category += c;
break;
case 2:
descript += c;
break;
case 3:
price += c;
break;
default:
error_encountered = true;
file.close();
return vector_menu_list;
}
}
else
{
addToList(vector_menu_list, itemNo, category, descript, price);
itemNo.clear();
category.clear();
descript.clear();
price.clear();
number_of_colons_encountered = 0;
}
}
addToList(vector_menu_list, itemNo, category, descript, price);
error_encountered = false;
}
else
{
error_encountered = true;
}
file.close();
return vector_menu_list;
}
int main()
{
bool error_encountered;
vector<MenuList*> p_menu_list = readFile("menu list.txt", error_encountered);
if (true == error_encountered)
{
return -1;
}
cout << "List menu items:" << endl;
for (unsigned long long i = 0; i < p_menu_list.size(); i++)
{
cout << p_menu_list.at(i)->itemNo << " ";
cout << p_menu_list.at(i)->category << " ";
cout << p_menu_list.at(i)->descript << " ";
cout << p_menu_list.at(i)->price << endl;
}
cout << "\n\nHere are only the prices: " << endl;
for (unsigned long long i = 0; i < p_menu_list.size(); i++)
{
cout << p_menu_list.at(i)->price << endl;
}
for (unsigned long long i = 0; i < p_menu_list.size(); i++)
{
delete p_menu_list.at(i);
}
return 0;
}