File of mixed content into an array

[Piratian]

Hello, I have a file consisting of items that I need into an array, and prices that I need into the array as well.

So far I have the array set up in a struct with string and double, but for the life of me I cannot get it to read an entire line into the array.

I have tried about 8 things so far but I don't remember how to do the getline and infile very well.

	string line;
	ifstream inFile;
	inFile.open("Ch9_Ex4Data.txt");
	if (!inFile) 
	{
		cout << "Input file open failure." << "Program terminating." << endl;
		system("PAUSE");
	}
	for(int i = 0; i < 8; i++)
	{
		inFile.getline(inFile, line) menuList[i].menuItem;
		inFile.getline(infile, line) menuList[i].menuPrice;
	}
	inFile.close();

Here is the file

Plain Egg
1.45
Bacon and Egg
2.45
Muffin
0.99
French Toast
1.99
Fruit Basket
2.49
Cereal
0.69
Coffee
0.50
Tea
0.75

[Tyler T]

I'm not sure what you wish to do. Does the std::string line already has the line you wish to read in it? If yes, reading the std::string into the struct should be easy. It should be this: (I'm assuming that by string you meant a std::string)

menuList[i].menuItem = line;
...//Get another line to get the price
menuList[i].menuPrice = stod(line); //stod() converts the input std::string into a double 

(But this doesn't make much sence...)
If not, then things get a little more complicated...
Inside the for loop:

char currentLine[256];
inFile.getline(currentLine, 256); //First parameter is the buffer you wish to read into, second the max number of chars to read
menuList[i].menuItem = currentLine;
inFlie.getline(currentLine, 256); //Read a second time to get the price line
line = currentLine;
menuList[i].menuPrice = stod(line); //stod() converts the input std::string into a double 

Hope this works.

[JLBorges]

> (But this doesn't make much sence...)

It does.

#include <iostream>
#include <string>
#include <fstream>
#include <iomanip>

struct menu_item
{
    std::string name ;
    double price = 0 ;
};

int main()
{
    const std::string file_name = "Ch9_Ex4Data.txt" ;

    // create the test file
    {
          std::ofstream(file_name) <<   "Plain Egg\n"
                                        "1.45\n"
                                        "Bacon and Egg\n"
                                        "2.45\n"
                                        "Muffin\n"
                                        "0.99\n"
                                        "French Toast\n"
                                        "1.99\n"
                                        "Fruit Basket\n"
                                        "2.49\n"
                                        "Cereal\n"
                                        "0.69\n"
                                        "Coffee\n"
                                        "0.50\n"
                                        "Tea\n"
                                        "0.75\n" ;
    }

    const std::size_t MAX_ITEMS = 8 ; // maximum possible number of items
    menu_item items[MAX_ITEMS] ;
    std::size_t num_items = 0 ; // actual number of items that were read from the file

    std::ifstream file(file_name) ; // open the file for input
    std::string name_str, price_str ;

    // try to read name and price as complete lines, up to a maximum of MAX_ITEMS
    while( num_items < MAX_ITEMS && std::getline( file, name_str ) && std::getline( file, price_str ) )
    {
        try
        {
            // try to convert the price read in as a string into a number
            // http://en.cppreference.com/w/cpp/string/basic_string/stof
            const double price = std::stod(price_str) ; // may throw if conversion fails

            // conversion was successful
            items[num_items].name = name_str ;
            items[num_items].price = price ;
            ++num_items ;
        }
        catch( const std::exception& )
        {
            // conversion failed
            std::cerr << "invalid price for item " << std::quoted(name_str) << ". item was ignored.\n" ;
        }
    }

    std::cout << "the following items were read from the file\n-------------------------\n" ;
    for( std::size_t i = 0 ; i < num_items ; ++i )
        std::cout << std::setw(15) << std::quoted(items[i].name) << ' ' << items[i].price << '\n' ;
}

http://coliru.stacked-crooked.com/a/dffef029ea28ef42

[Piratian]

I have an array of .menuitem and .menuprice, and I was looking for a way to read the file into the array. I didn't know what to put to read on an entire line since issuing infile >> only went to a white space

[Tyler T]

Use ifstream::getline(). First parameter is the buffer you wish to read into, second is the max number of chars to read. More info at http://www.cplusplus.com/reference/istream/istream/getline/