I'm trying to allow the user to modify values from a data file. I'm using class members to hold the value as well as an array
#include <iostream>
#include <fstream>
using namespace std;
class student
{
private:
string stuID;
string lastN;
string firstN;
float GPA;
int numb_of_enrolled;
public:
void displayAll();
void setAll(string StuID, string LastN, string FirstN, float gpa, int nof);
};
const int SIZE = 30;
int main()
{
ifstream inFile;
int option, count, scount = 0, cIndex;
student stuFile[SIZE];
string sID, sLN, sFN;
float sgpa;
int snof;
char repeat = 'y';
inFile.open("Students.dat", ios::in);
cout << "MENU\n";
cout << "3. Change an Existing Record's Fields\n";
cout << "What would you like to do?: ";
cin >> option;
cin.ignore();
switch(option) {
case 3:
inFile >> sID >> sLN >> sFN >> sgpa >> snof;
cout << "There are 19 Students in this data file\n";
cout << "Enter an Index from 0 - 19: ";
cin >> cIndex;
cin.ignore();
stuFile[cIndex].setAll(sID, sLN, sFN, sgpa, snof);
stuFile[cIndex].displayAll();
}
}
void student::displayAll()
{
cout << "Student ID: " << stuID << endl;
cout << lastN << ", " << firstN << endl;
cout << numb_of_enrolled << " Classes taken this Semester\n";
cout << "Current GPA is: " << GPA << "\n\n";
}
void student::setAll(string StuID, string LastN, string FirstN, float gpa, int nof)
{
stuID = StuID;
lastN = LastN;
firstN = FirstN;
GPA = gpa;
numb_of_enrolled = nof;
}
So the data file has 19 records inside of it. Case 3 works but not how it should. If I enter 3, it doesn't go to the third record inside of it but it stays at 0. Even if I use .eof(), it would still be stuck at element 0. How can I make it so that I'm able to get to the record I want?
You need to loop for N lines for the cIndex, declare int i and do this code
case 3:
cout << "There are 19 Students in this data file\n";
cout << "Enter an Index from 0 - 19: ";
cin >> cIndex;
cin.ignore();
for(i=0;i<cIndex;i++) {
inFile >> sID >> sLN >> sFN >> sgpa >> snof;
}
stuFile[cIndex].setAll(sID, sLN, sFN, sgpa, snof);
stuFile[cIndex].displayAll();
inFile.clear();
inFile.seekg(0);
Related
For one of my options, I had to add a row of data to my struct array, I was able to update the array but it does not update the actual array. So I am trying to update my struct array by passing it as a reference. I placed the '&' sign before the name of the variable, but all my indexes within the function errored.. I'm still a newbie to programing and I'm not "allowed " to use any vectors according to my Professor. . I looked online and placed the '&' on the function name as well as on the prototype. I also changed it from void to the "data type" to return the updated array, but no luck... I hope this comes out clear....
#include<iostream>
#include<iomanip>
#include<fstream>
using namespace std;
struct Data {
string first_name;
string last_name;
int employee_id;
string phone_number;
};
void readFile( ifstream& , string, Data [],int&);
void getEmployeeDetail(Data [], int&);
void getEmployeeLast(Data [], int&);
Data getAddEmployee(Data &, int&);
void getRemoveEmployee();
void getManagerOnly();
void getStaffOnly();
const int SIZE = 15;
Data employee[SIZE];
int main() {
ifstream inputFile;
ofstream outputFile;
int count = 0;
int selection;
const int EMPLOYEE_DETAIL = 1,
EMPLOYEE_LAST = 2,
ADD_EMPLOYEE = 3,
REMOVE_EMPLOYEE = 4,
MANAGER_ONLY = 5,
STAFF_ONLY = 6,
QUIT = 7;
readFile( inputFile ,"employeeData.txt", employee,count);
do {
cout << "\t Please select your option.\n"
<< "1. List all employee details\n"
<< "2. List employee by last name\n"
<< "3. Add a new employee\n"
<< "4. Remove an employee\n"
<< "5. Show all managers only\n"
<< "6. Show all staff only\n"
<< "7. Quit\n"
<< "Please enter your selection.\n" << endl;
cin >> selection;
while (selection < EMPLOYEE_DETAIL || selection > QUIT) {
cout << " Pleasse enter a valid selection.\n";
cin >> selection;
}
switch (selection) {
case EMPLOYEE_DETAIL:
getEmployeeDetail(employee,count);
break;
case EMPLOYEE_LAST:
getEmployeeLast(employee, count);
break;
case ADD_EMPLOYEE:
getAddEmployee(employee, count);
break;
case REMOVE_EMPLOYEE:
getRemoveEmployee();
break;
case MANAGER_ONLY:
getManagerOnly();
break;
case STAFF_ONLY:
getStaffOnly();
break;
case QUIT:
cout << "Program ending\n";
break;
}
} while (selection != QUIT);
system("pause");
return(0);
}
void readFile(ifstream& inputFile, string data, Data employee[],int &count) {
inputFile.open(data);
if (!inputFile) {
cout << " Error in opening file\n";
exit(1);
}
else {
while (!inputFile.eof()) {
inputFile >> employee[count].first_name;
inputFile >> employee[count].last_name >> employee[count].employee_id >> employee[count].phone_number;
count++;
}
inputFile.close();
}
return;
};
void readFile(ifstream& inputFile, string data, Data employee[],int &count) {
inputFile.open(data);
if (!inputFile) {
cout << " Error in opening file\n";
exit(1);
}
else {
while (!inputFile.eof()) {
inputFile >> employee[count].first_name;
inputFile >> employee[count].last_name >> employee[count].employee_id >> employee[count].phone_number;
count++;
}
inputFile.close();
}
return;
};
void getEmployeeDetail( Data employee[], int& count) {
cout << "Firt Name" << "\t" << "Last Name " << "\t" << "Employee ID " << "\t" << "Phone Number \n";
cout << "--------------------------------------------------------------------------\n";
for(int i =0; i < count; i++)
cout <<employee[i].first_name<<"\t\t"<<employee[i].last_name<<"\t\t"<<employee[i].employee_id<<"\t\t"<<employee[i].phone_number<< "\n ";
cout << endl;
}
void getEmployeeLast(Data employee[], int& count) {
string searchName;
cout << "Please enter the last name of the employee you want to search for.\n";
cin >> searchName;
/*
for (int i = 0; i < count; i++)
if (searchName ==employee[i].last_name) {
cout << employee[i].last_name;
}
*/
string matchString = searchName;
for (int i = 0; i < count; i++) {
if (employee[i].last_name.find(matchString, 0) != std::string::npos) {
cout << employee[i].last_name << endl;
}
else {
cout << "No employee was located with that name.\n";
exit(1);
}
}
}
Data getAddEmployee(Data &employee, int& count) {
string firstName, lastName, phoneNumber;
int employeeID, size;
for (int i = 0; i < count; i++)
cout << employee[i].first_name << "\t\t\t" << employee[i].last_name << "\t\t" << employee[i].employee_id << "\t\t" << employee[i].phone_number << "\n ";
cout << endl;
cout << count <<"\n";
size = count + 1;
cout << size << "\n";
cout << "Please enter the new employee First Name.\n";
cin >> firstName;
cout << "Please enter the new employee Last Name.\n";
cin >> lastName;
cout << "Please enter the new employee's ID.\n";
cin >> employeeID;
cout << "Please enter the new employee Phone Number.\n";
cin >> phoneNumber;
employee[10].first_name = firstName;
employee[10].last_name = lastName;
employee[10].employee_id = employeeID;
employee[10].phone_number = phoneNumber;
for (int i = 0; i < size; i++) {
cout << employee[i].first_name << "\t\t\t" << employee[i].last_name << "\t\t" << employee[i].employee_id << "\t\t" << employee[i].phone_number << "\n ";
cout << endl;
}
return employee;
}
First of all, your naming could be better. Like employeeList instead employee to specify its a list/array of employee, also addEmployee instead of getAddEmployee.
Second, instead of pasting whole code, it's better to paste the relevant block of code based on your question to make it clearer.
The solution is, your array is basically already on global scope, you don't need to pass it. Can just directly modify the array.
struct Data {
string first_name;
string last_name;
int employee_id;
string phone_number;
};
void addEmployee();
const int SIZE = 15;
Data employeeList[SIZE];
int current = 0;
int main(){
Data emp1 = {"John", "Doe", 100, "12345"};
employeeList[0] = emp1;
current++;
addEmployee();
for(int i=0; i<current; i++){
Data emp = employeeList[i];
cout<<i+1<<" "<<emp.first_name<<" "<<emp.phone_number<<endl;
}
}
void addEmployee(){
Data emp2 = {"Sam", "Smith", 200, "67890"};
employeeList[current] = emp2;
current++;
}
Can try it here: https://onlinegdb.com/drhzEOpis
I am new to programming, and I am currently trying to figure my way around C++. I am working on a program that will display basic information about employees to the users, and I want the program to end when the users entered a char. However, while working through it, I encountered a problem. When I enter the char (x), it somehow looped from 1-120 (as you seen in the counter below), but when I entered its ASCII number (120), it ended the program as intended. Can anyone explain it to me and what are the possible solutions?
#include <iomanip>
#include <iostream>
using namespace std;
class Employee
{
public:
int Age;
string Name;
int ID;
void information()
{
cout << "Name: " << Name << endl;
cout << "Age: " << Age << endl;
cout << "ID: " << setfill('0') << setw(3) << ID << endl;
}
Employee(string name, int age, int id)
{
Name = name;
Age = age;
ID = id;
}
};
void createProfile()
{
int age;
int id;
string name;
cout << "Enter the Employee Name: ";
cin >> name;
cout << "Enter the Employee Age: ";
cin >> age;
cout << "Enter the Employee ID: ";
cin >> id;
}
int main()
{
int num, counter;
const char stop = 'x';
cout << "Choose an Employee " << endl;
cout << "001 Jack" << endl;
cout << "002 Susan" << endl;
cout << "003 to create profile" << endl;
cout << "Press x to Exit";
for (num = 0; num != stop; num++)
{
cout << "\n\nEnter the Employee ID: ";
cin >> num;
counter += 1;
if (num == 001)
{
Employee jack = Employee("Jack", 25, 001);
jack.information();
}
else if (num == 002)
{
Employee jack = Employee("Susan", 23, 002);
jack.information();
}
else if (num == 003)
{
createProfile();
}
else
{
cout << "Input invalid";
}
}
cout << "\n" << counter;
}
Yes, of course. In C/C++, char is a type that can be represented either by its character value ('A', for example) or its numeric value (65). However, a digit's numeric value does not equal to itself.
'1' == 49
120 is the ASCII value of lower case x and since you loop with an int, it is logical that it will end up working in ways you do not expect it to work. You can change your
for (num = 0; num != stop; num++)
to
for (num = 0; ch != stop; num++)
and of course ch should be declared as char before your loop. Also, make sure that you replace cin >> num; with cin >> ch;
The code :
class DataBase {
private:
int age, stuNumNew;
string stuName, command;
string ver = "Alpha";
float stuNum = 1;
public:
void Start() {
cout << "Welcome back to Sudent DataBase <ver " << ver << ">." << endl;
cout << "Type 'Add' for add a student.";
cin >> command;
if (command == "Add") {
Add();
}
else if (command == "Search") {
cout << "Student number: ";
cin >> stuNumNew; //Get input from user
cout << "Name: " << stuName[stuNumNew] << endl << "Age: " << age[&stuNumNew] << endl;
Start();
}
}
void Add() {
cout << "Name: ";
**cin >> stuName[stuNum] * *; //get the name
cout << "Age: ";
cin >> age[stuNum]; //get the age
cout << "Student Number: " << stuNum;
stuNum = stuNum++;
stuNumNew = stuNum;
Start();
}
};
Vectors allow you to create variable size arrays
The issue you're having is caused by using a fixed size variable. What you need in this case is a vector because what you are trying to do is assign names and numbers to arrays that are of variable sizes so that you can add new students in your program.
Vectors allow you to do just that.
Here is the modified code:
#include <iostream>
#include <string>
#include <vector>
using namespace std;
class DataBase {
private:
int searchInput;
/* declare a vector of type int to contain your students' ages */
vector<int> studentAges;
/* declare a vector of type std::string to contain your students' names */
vector<string> studentNames;
string command;
string ver = "Alpha";
/* stuNum is removed because vectors keep track of their own sizes */
public:
void Start() {
cout << "Welcome back to Student DataBase <ver " << ver << ">." << endl;
cout << "Type 'Add' to add a new student or type 'Search' to search the database of students." << endl << " > ";
cin >> command;
if (command == "Add") {
Add();
} else if (command == "Search") {
/* You may want to build in a conditional that checks if there are any students yet. */
cout << "Student number: ";
cin >> searchInput;
if (searchInput < studentNames.size()) {
/* Make sure that the users input (the number) is actually a student's id number
* otherwise reject their input to keep the program from crashing or having undefined behavior.
*/
cout << "Name: " << studentNames[searchInput] << endl << "Age: " << studentAges[searchInput] << endl;
} else {
cout << "Student number invalid" << endl;
}
} else {
/* Tell them if their input is invalid */
cout << "Invalid option." << endl;
}
Start();
}
void Add() {
/* Append new positions for input */
studentNames.push_back("");
studentAges.push_back(0);
cout << "Name: ";
cin >> studentNames.back();
cout << "Age: ";
cin >> studentAges.back();
/* The student number is the newest index of the vector */
cout << "Student Number: " << studentNames.size() - 1 << endl;
}
};
int main() {
DataBase d;
d.Start();
}
You can also combine your variables studentNames and studentAges into a students vector if you create a class (or struct) that keeps both values together:
class Student {
public:
Student(string name, int age) {
this->age = age;
this->name = name;
}
string name;
int age;
};
Then you can use it with vector:
vector<Student> students;
NOTE:
You may want to add some input protecting because if you enter a string where it wants a number it breaks the program.
I have a project where I need to create a shopping list with checkout functionality. I am trying to create an array using a users input. They supply how many products they are purchasing and I need to use that to define the size of the array.
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
struct shopList {
double pluCode;
string product;
int saleType; // 0 = per unit, 1 = per pound
double price;
double inventory;
};
int main(){
char line[255];
const int items = 0;
int n;
ofstream outfile;
outfile.open("products.txt");
cout << "How many items in your checkout: ";
cin >> items;
shopList shop[items];
for (n = 0; n < items; n++) {
cout << "Enter the PLU code: ";
cin >> shop.pluCode;
outfile << shop.pluCode << " ";
cout << "Enter product name: ";
cin >> shop.product;
outfile << shop.product << " ";
cout << "Enter the price type (0 for per unit, 1 for per pound): ";
cin >> shop.saleType;
outfile << shop.saleType << " ";
cout << "Enter the price of the product: ";
cin >> shop.price;
outfile << shop.price << " ";
cout << "How much will you purchase: ";
cin >> shop.inventory;
outfile << shop.inventory << " " << "\n";
}
outfile.close();
ifstream infile;
infile.open("products.txt");
infile.getline(line, 255);
cout << line << endl;
}
It's possible , you just have to change your declaration like that;
int items = 0 ;
cin >> items;
shopList *shop = new shopList [items];
thanks for your anticipated help. I have been looking at this code for hours and days but I just cant seem to find out why my delRecFunc() isn't deleting just one record at a time. It appears it is deleting the whole file.
#include <iostream>
#include <fstream>
#include <stdlib.h>
#include <string>
#include <iomanip>
using namespace std;
const int NAME_SIZE = 40, ADDR_SIZE = 50, PHONE_SIZE = 14;
char y, Y;
struct Info
{
char name[NAME_SIZE];
int age;
char address1[ADDR_SIZE];
char phone[PHONE_SIZE];
}people;
void popFunc();
void dispFunc();
void appFunc();
void delRecFunc();
void searchFunc();
void modRecFunc();
int getNumRec();
int validateRecord (int);
void wipeFunc();
int main()
{
Info person;
char choice, option;
cout << " The file we are working with is named stuff.dat,\n"
<< "I will let you know if it unavailable " << endl;
cout << " "<< endl;
do
{
cout << " \n \n Simple People Records... \n \n \n "
<< " Please choose from the following options: \n \n \n"
<< " 1. POPULATE THE BINARY FILE \n"
<< " 2. DISPLAY THE CONTENTS OF THE FILE\n"
<< " 3. APPEND A RECORD TO THE FILE\n"
<< " 4. DELETE A RECORD FROM THE FILE\n"
<< " 5. SEARCH FOR A CERTAIN RECORD\n"
<< " 6. MODIFY A CERTAIN RECORD. \n"
<< " 7. WIPE OUT THE ENTIRE CONTENTS OF THE FILE. \n" <<endl;
cin >> option;
switch(option)
{
case '1': popFunc();
system("pause");
break;
case '2': dispFunc();
break;
case '3': appFunc();
break;
case '4': delRecFunc();
break;
case '5':searchFunc();
break;
case '6':modRecFunc();
break;
case '7':wipeFunc();
break;
}
}
while(choice!= 1000);
system("pause");
return(0);
}
void popFunc()
{ fstream file("stuff.dat", ios::out | ios::binary);
if (file.fail())
{
cout << "the file does not exist so we are creating it now... ";
system("pause");
file.open("stuff.dat", ios::out);
}
cout << "enter the following data about a person: "<<endl;
cout << "Name: " <<endl;
cin >> ws;
cin.getline(people.name,NAME_SIZE);
cout << "Age (integers only or the program will be corrupted): " <<endl;
cin >> people.age;
cin.ignore(); //skip over the remaining newline.
cout<< "Address line 1: ";
cin >> ws;
cin.getline(people.address1,ADDR_SIZE);
cout << "Phone: in the following format ie: 201.123.1234 (no hyphens)";
cin >> ws;
cin.getline(people.phone,PHONE_SIZE);
file.write(reinterpret_cast<char *>(&people), sizeof(people));
file.close();
}
void dispFunc()
{
ifstream file;
file.open("stuff.dat", ios::binary);
if (file.fail())
{
cout << "the file does not exist so we are creating it now... ";
system("pause");
file.open("stuff.dat", ios::out);
}
while(file.read(reinterpret_cast<char *> (&people), sizeof(people)))
{
cout << "Name: "<< people.name <<endl;
cout << "Age: "<< people.age <<endl;
cout << "Address: " <<people.address1 <<endl;
cout << "Phone #: " <<people.phone << " \n\n"<<endl;
}
file.close();
}
void appFunc()
{ ofstream file;
file.open("stuff.dat", ios::binary | ios::app);
if (file.fail())
{
cout << "the file does not exist so we are creating it now... ";
system("pause");
file.open("stuff.dat", ios::out);
}
cout << "Name: " <<endl;
cin >> ws;
cin.getline(people.name,NAME_SIZE);
cout << "Age (integers only or the program will be corrupted): " <<endl;
cin >> people.age;
cin.ignore(); //skip over the remaining newline.
cout<< "Address line 1: ";
cin >> ws;
cin.getline(people.address1,ADDR_SIZE);
cout << "Phone: Phone: in the following format ie: 201.123.1234 (no hyphens)";
cin >> ws;
cin.getline(people.phone,PHONE_SIZE);
file.write(reinterpret_cast<char *>(&people), sizeof(people));
file.close();
}
void searchFunc()
{
int count =1;
int answer;
long recNum;
int recCount = getNumRec();
fstream search;
search.open("stuff.dat", ios::in | ios:: binary);
cout << " Please enter 1 - " <<recCount ;
cout << " and I will display the data /n"<<endl;
cin >>recNum;
while(recNum<1 || recNum > recCount)
{
cout<<"Please enter a number between 1 and "<<recCount<<": ";
cin>>recNum;
}
answer = validateRecord(recNum);
}
void modRecFunc()
{
int count=1;
int answer;//to hold choice from the user
long recNum;//to hold a record number
int recCount = getNumRec();//variable to hold how many record the file has
fstream search;
//open file
search.open("stuff.dat",ios::in|ios::out|ios::binary);
cout<<"Which record do you wish to edit? ";
cin>>recNum;//variable to store the record the user wish to delete
//validation so the user is not allow to enter more numbers than the actual
//size of the file
while(recNum<1||recNum>recCount)
{
cout<<"Please enter a number between 1 and "<<recCount<<": ";
cin>>recNum;
}
//move pointer to desire position
cout<<endl;
answer= validateRecord(recNum);//make sure the record is the right one
cout<<endl;
if(answer==1)
{
//get the new data
cout << "Name: " <<endl;
cin >> ws;
cin.getline(people.name,NAME_SIZE);
cout << "Age (integers only or the program will be corrupted): " <<endl;
cin >> people.age;
cin.ignore(); //skip over the remaining newline.
cout<< "Address line 1: ";
cin >> ws;
cin.getline(people.address1,ADDR_SIZE);
cout << "Phone: Phone: in the following format ie: 201.123.1234 (no hyphens)";
cin >> ws;
cin.getline(people.phone,PHONE_SIZE);
search.seekp((recNum-1)*sizeof(people), ios::beg);
search.write(reinterpret_cast<char *>(&people), sizeof(people));
}
cout<<endl;
search.close();
}
void wipeFunc()
{ char option;
ofstream file;
cout << "This option will delete all the contents of the file "<<endl;
cout << " Are you sure you want to delete the file? Y or N " <<endl;
cin >> option;
if (option == 'y' || option == 'Y')
{
cout << " Warning, if you hit Y, you will lose everything " <<endl;
cout << " Y to confirm, N to return to main menu" <<endl;
cin >> option;
if(option == 'y' || option == 'Y')
{
file.open("stuff.dat", ios::out | ios::binary);
file.close();
}
}
}
int validateRecord (int recNum)
{
int answer;// variable to hold the answer from the user
fstream validate;
//open file
validate.open("stuff.dat",ios::in|ios::out|ios::binary);
validate.seekg((recNum-1)*sizeof(people));
//read record from file
validate.read(reinterpret_cast<char*>(&people),sizeof(people));
cout<<endl;
cout << "the name is "<< people.name <<endl;
cout << "the age is "<< people.age <<endl;
cout << "the address is" <<people.address1 <<endl;
cout << "the phone is Phone: " <<people.phone <<endl;
cout<<"Is this the file you want?\n"
"1. yes\n"
"2. no\n"
"Choice: ";
cin>>answer;
// validate answer to 1 or 2
while(answer<1||answer>2)
{
cout<<"enter only 1 or 2: ";
cin>>answer;
}
cout<<endl;
validate.close();
return answer;
}
int getNumRec()
{
int count =0;
fstream file;
file.open("stuff.dat", ios::in|ios::binary);
if (file.fail())
{
cout << "Error opening file. Program aborting.\n";
}
file.read(reinterpret_cast<char *>(&people),sizeof(people));
while (!file.eof())
{
count++;
file.read(reinterpret_cast<char *>(&people),
sizeof(people));
}
file.close();//close the file
return count;//return count the erase function
}
void delRecFunc()
{
int count=1;
int answer; //to hold choice from the user
double recNum;//to hold the record number the user wishes to delete
int recCount = getNumRec();//variable to hold how many record the file has
fstream erase;
erase.open("stuff.dat", ios::in|ios::out|ios::binary);
Info Temp; //*****NEW TEMP STRUCT VAR*****//
cout << "Please enter the phone number of the person you want to delete in this
format 201.123.1111)";
cin >> recNum;
//move pointer to desire position
erase.seekg((recNum-1)*sizeof(people));
//read record from file
erase.read(reinterpret_cast<char*>(&people),sizeof(people)); //read record from file
//get answer from the validateRecord function
answer = validateRecord (recNum);
if(answer == 1)
{
ofstream copy;
copy.open("stuff2.dat", ios::out | ios::binary);
erase.seekg(0*sizeof(people)); // Move pointer to beginning of the file
erase.read(reinterpret_cast<char*>(&people),sizeof(people));
// BEGIN NEW CODE //
// Keep looping till there are no more records in the customer.dat file
while (!erase.eof())
{
// If the id that the user wants deleted doesnt match the current
// records id, copy it to the temp directory
if(people.phone != Temp.phone)
{
// Write the record to copy.dat
copy.write(reinterpret_cast<char*>(&people),sizeof(Info));
}
// Read the next line from customer.dat
erase.read(reinterpret_cast<char*>(&people),sizeof(Info));
}
// Close both files
erase.close();
copy.close();
}
// Delete the Old customer.dat file
remove("stuff.dat");
// Rename the temporary holder to "customer.dat"
rename("stuff2.dat","stuff.dat");
}
You're taking an improperly formatted double (inputted from the cin >> recNum), seeking that far (*sizeof(people) into the file, and going from there. Seems like you need to start there.
Looks like you are entering the phone number in recNum (in the format 201.123.1111) and doing a seekg, which will give incorrect results