Area Codes Help!

You need to read the whole file, and "insert" the area code and name into your map before you try to search your "database" for the information.

Hello Unisaurus,

You have a good start to your program. I will suggest that at line 28 you should check to make sure the file is open. Use this code if you like:

if (inFile.is_open())
{
	std::cout << "\n File " << fileName << " is open" << std::endl;
	//Sleep(SLEEP_TIME);
}
else
{
	std::cout << "\n File " << fileName << " did not open" << std::endl;
	Sleep(SLEEP_TIME);
	exit(1);
}

I use the Sleep() function until I find something different. It has not been important yet.

Line 34 I do not believe that the condition will work. I am thinking it will always evaluate to true. Also StatName is a string not a map, so I do not think the ,begin() and .end() will not work the way you are thinking.

Line 40 the while statement is mostly wrong. Line 48 should be just above line 59. And line 46 is the wrong place to rad the file. It should be earlier when you load the map.

After you open the file then you need to load the map. These links should help:
http://www.cplusplus.com/reference/map/map/
http://www.cplusplus.com/reference/map/map/map/

Hope that helps,

Andy

Thanks so much for the help Andy!! Yeah I'm tryin to learn what and how to use the map lol. I'll post more of my code by the end of the weekend.

Okie dokie here is some updated code!

#include <iostream>
#include <fstream>
#include <map>
#include <string>
#include <sstream>
#include <windows.h>


using namespace std;



int main()
{

	map<int, string> States;


	ofstream inputFile;
	string fileName;
	string StateName;
	string num;
	

	cout << "Enter the file name: ";
	cin >> fileName;

	
	inputFile.open(fileName.c_str());


	cout << "Enter the State name: ";
	cin >> StateName;


	if (inputFile)
	{
		while (!inputFile.eof()) // a check for we are not at the end of file.
		{

			
			 cout << num.substr(0, 3);
			inputFile << StateName; // we are reading from a file....
			inputFile << num;
			
			cout << "Word Number " <<  ": " << StateName << num << endl;

		}

		inputFile.close();
	}
	else
	{
		cout << "We had a problem with the file!!!" << endl;
	}


	

	inputFile.close();



	cin.ignore();
	cin.get();
	return 0;


	
}

Please any help is appreciated.

Okie dokie I can read and print all of the area code numbers so now I just need it specifically find the certain states numbers.

#include <iostream>
#include <fstream>
#include <map>
#include <string>
#include <sstream>
#include <windows.h>


using namespace std;



int main()
{

	map<int, string> States;


	ifstream inputFile;
	string fileName;
	string StateName;
	int num;
	

	cout << "Enter the file name: ";
	cin >> fileName;

	
	inputFile.open(fileName);


	cout << "Enter the State name: ";
	cin >> StateName;


	if (inputFile)
	{
		while (!inputFile.eof()) // a check for we are not at the end of file.
		{
			
			while (getline (inputFile, StateName))
			{

				 
					inputFile >> num;
					cout << num << endl;
				
			}
		
		}

		inputFile.close();
	}
	else
	{
		cout << "We had a problem with the file!!!" << endl;
	}


	

	inputFile.close();



	cin.ignore();
	cin.get();
	return 0;


	
}

Why do you have that map<>?

Have you considered using it somehow?

Hello Unisaurus,

As jlb said you have defined a map called “States”, but you have never used it as the instructions call for.

Your outer while loop at line 38 is not needed and checking for “eof” is bad form and may not work as you might expect. You will reach “eof” before you can check for it.

The inner while loop at line 41 is where you will need to load the map. I read a single line from the file with
while (getline(inputFile, line))
Then I used a stringstream to break up the line into the area code and state name then change the area code which is a string to a number for variable “num” before storing the two pieces of info into the map.
Following the while loop I created an iterator to use in a for loop to printing out the area codes for a state. Followed by an input for which state to find. Then a for loop to loop through the map to match the state and print the area code(s) for that state.

Today I had the thought to add code if no match was found.

The two links from my earlier post http://www.cplusplus.com/forum/beginner/202015/#msg962523 will help to understand using “map”.

Hope that helps,

Andy

Yeah I keep forgetting about the map because my professor just requested us to use it and I have no idea about it I just know what it stands for... but thank you guys so much for the help! I'll try and post what I have updated later tonight.

Okay this is as far as i've gotten today, i'll try some more tomorrow and its due on sat! Trying my best to learn and write good code. Any help is again appreciated.

#include <iostream>
#include <fstream>
#include <map>
#include <string>
#include <sstream>
#include <windows.h>


using namespace std;



int main()
{

	map<int, string> States;


	ifstream inputFile;
	string fileName;
	string StateName;
	string line;
	string num;
	

	cout << "Enter the file name: ";
	cin >> fileName;

	
	inputFile.open(fileName);


	cout << "Enter the State name: ";
	cin >> StateName;


	if (inputFile)
	{
		
			while (getline (inputFile, line))
			{
				
				stringstream iss(line); // I used this and the last two and it printed out the area codes and the states...not sure if I'm going in the right direction or not.
				int num = atoi(num);  //Not sure if I need this and for some reason it will NOT turn to a int i've tried everything I know and googled some stuff...
				States.insert(pair <int, string> (num, StateName)); // Or this
				getline(iss, num);
				cout << num << endl;
				
			}
		
			for (int a = 0; a < num; a++)
			{




			}

		inputFile.close();
	}
	else
	{
		cout << "We had a problem with the file!!!" << endl;
	}


	

	inputFile.close();



	cin.ignore();
	cin.get();
	return 0;


	
}

Okay using a stringstream to process isn't a bad idea, but you don't need atoi(), that's where the stringstream comes into play:

    while(getline(inputFile, line))
    {
        // Use a stringstream help parse each line.
        stringstream iss(line);
        // Now parse each line, first strip off the area code and the dash.
        char dash;
        // Get the area_code the retrieve and discard the dash.
        iss >> area_code >> dash;
        // Now get the state/province name.
        getline(iss, state_name);

        // Now print the two variables to see that you've properly read the "file".
        cout << "Area code " << area_code << " is in " << state_name << endl;

        // Here is where you need to populate your map.
 

    }

Hint you don't really need make pair, just use array notation to add the key/value to the map.
http://www.cplusplus.com/reference/map/map/operator[]/

And by the way you really don't need to close your input file, let the class destructor do it's job, it'll automatically close the file when the stream goes out of scope.

Hello Unisaurus,

Basd on what I did and what you have it would work better this way:

while (getline(inputFile, line))
{

	stringstream iss(line); // I used this and the last two and it printed out the area codes and the states...not sure if I'm going in the right direction or not.
	std::gtline(iss, snum, '-'); // snum is a string and this line will extract from the stringstream u to the '-', but not including the '-'.
	std::getline(iss, StateName); // This will extract the state name after the '-'.
	int num = atoi(snum);  // snum is defined as type string. Same concept as what you have, but easier to understand.
	States.insert(pair <int, string>(num, StateName)); // Or this
	//States.insert(make_pair(num, StateName));  // I believe this is the correct way to code the above line. As jlb said you do not need to add to
                                                     // the map this way I just thought it was a better way to build a map of unknown size.You can set
                                                     // this up any way you like.

	cout << num << endl;
}

Based on your last bit of code line 46 is not needed. The condition of the while loop will do the job. Line 44 does not work because you have taken nothing fro the stringstream and put it in "num". Also using the same name (num) for two different types is a bad idea. Even if it compiles it is hard to know which one is which.

Or based on jlb's suggestion you might try this. A bit cleaner and I see the truth in it now.

while (getline(inputFile, line))
{

	stringstream iss(line); // I used this and the last two and it printed out the area codes and the states...not sure if I'm going in the right direction or not.
	iss >> num >> dash;
	getline(iss,  StateName); // Corrected
	States.insert(make_pair (num, StateName)); // Or this
	cout << num << endl;
}

Hope that helps,

Andy

Edited to correct earlier mistake.

Last edited on

iss >> StateName;

This won't work, several of the StateNames have spaces, the insertion operator>> stop processing strings when it encounters a whitespace character.

Your call to atoi() will not be needed if you use the proper type of variable in the first place (an int). In my snippet area_code is declared as an int, not a string. By the way atoi() really shouldn't be used in a C program much less a C++ program, this C function can silently fail, plus this function expects a C-string not a C++ std::string.

And as I stated in my last post you can use "array" notation to insert the key/values into the map, instead of the make_pair() call.

    ...
    std::map<int, std::string> areaCodes;

    string line, StateName;
    int area_code; 
    while(getline(inputFile, line))
    {
        // Use a stringstream help parse each line.
        stringstream iss(line);
        // Now parse each line, first strip off the area code and the dash.
        char dash;
        // Get the area_code the retrieve and discard the dash.
        iss >> area_code >> dash;
        // Now get the state/province name.
        getline(iss, state_name);

        // Now print the two variables to see that you've properly read the "file". Can be removed after degugging.
        cout << "Area code " << area_code << " is in " << state_name << endl;

        // Here is where you need to populate your map.
        areaCodes[area_code] = state_name;
    }

    // Print out the map contents.
    for(auto& mm : areaCodes)
        cout << "Area code " << mm.first << " is in " << mm.second << endl;

@jlb,

Thanks I missed that when I was typing. Think to far ahead.

Andy

Okie dokie I'm starting to get it now. However the only thing I have to do now is only print out the certain area codes for the specific state that you type in. Other than that it prints everything out nicely!

However the only thing I have to do now is only print out the certain area codes for the specific state that you type in.

If you need to look up the states to print each area code for that state then you probably shouldn't be using a map. A map is designed for quick lookup based on the key, which in this case is the area code, and the key must be unique. I would recommend either a std::multimap<string, int> if you need to print each area code for a state. Another option would be to use a class/structure that holds the area code and state name, then create a vector of this class to hold the information. You can then sort the vector for the proper "lookup" order.

Okie dokie thanks sadly I have to use a map my professor said that I have to use it...specifically this :

Write a C++ program that reads the file into a STL
Map<int, string> where the key is the area code and the value is the location.

Gah Im super confused this professor is horrid!

** On the map should I put the string then the int first? So that way it can look for the state than look for the area codes?

Last edited on

On the map should I put the string then the int first? So that way it can look for the state than look for the area codes?

No, you have duplicate state names and the key must be unique.

So I think maybe I might be on to something but I have until midnight of today (19th) to have this done... lol so kinda in panic mode.

#include <iostream>
#include <fstream>
#include <map>
#include <string>
#include <sstream>
#include <windows.h>


using namespace std;



int main()
{

	map<int, string> States;
	

	ifstream inputFile;
	string fileName;
	string StateName;
	string line;
	int num;
	

	cout << "Enter the file name: ";
	cin >> fileName;

	
	inputFile.open(fileName);


	cout << "Enter the State name: ";
	cin >> StateName;


	if (inputFile)
	{
		
		while (getline(inputFile, line))
		{
			char dash;
				// Use a stringstream help parse each line.
				stringstream iss(line);

				iss >> num >> dash; // I figured I would put this hear to strip off the area code so that it could find the  state...

				if (line == StateName)
				{
					cout << num << endl;
					// Now parse each line, first strip off the area code and the dash.
					char dash;
					// Get the area_code the retrieve and discard the dash.
					iss >> num >> dash;
					// Now get the state/province name.
					getline(iss, StateName);
				}
			
				
			// Here is where you need to populate your map.
			States[num] = StateName;
		}

		// Print out the map contents.
		for (auto& mm : States)
			cout << "Area code " << mm.first << " is in " << mm.second << endl;

			
	}
	else
	{
		cout << "We had a problem with the file!!!" << endl;
	}


	



	cin.ignore();
	cin.get();
	return 0;


	
}