How to read/write doubles in a binary file? - c++

I am creating a program that will write and read the content of a binary file. The part I am struggling with is reading/writing pointsEarned and studentGPA as a double. It prints out 6.36599e-314 instead of the number I provided. I looked around the web for a solution but couldn't find one, so here I am.
class student {
int studentID;
char name[30];
char lastName[30];
double pointsEarned;
double studentGPA;
public:
void getData() {
cout << "\nEnter the Student ID: ";
cin >> studentID;
cout << "\n\nEnter the first name of the student: ";
cin >> name;
cout << "\n\nEnter the last name of the student: ";
cin >> lastName;
cout << "\n\nEnter the amount of points earned by the student: ";
cin >> pointsEarned;
cout << "\n\nEnter the Student GPA: ";
cin >> studentGPA;
}
void showData() {
cout << "\nStudent ID: " << studentID;
cout << "\nStudent Name: " << name << " " << lastName;
cout << "\nPoints: " << pointsEarned;
cout << "\nGPA: " << studentGPA << "\n";
}
int studentNumber() {
return studentID;
}
};
//input student info into the dat file
void write() {
student object;
student val;
ofstream file2;
file2.open("student.dat", ios::binary | ios::app);
object.getData();
file2.write((char *)&object, sizeof(object));
file2.close();
}
void display() {
student object;
ifstream file1;
file1.open("student.dat", ios::binary);
if (!file1) {
cout << "File not Found!\n";
}
else {
//read data
while (file1.read((char *)&object, sizeof(object))) {
object.showData();
}
}
file1.close();
}
//display student information through their studentID
void search(int n) {
student object;
ifstream file1;
file1.open("student.dat", ios::binary);
if (!file1) {
cout << "File not Found!\n";
}
else {
while (file1.read((char *)&object, sizeof(object))) {
if (object.studentNumber() == n)
object.showData();
//validation
if (object.studentNumber() != n) {
cout << "StudentID doesn't exist\n";
break;
}
}
}
file1.close();
}
//delete student
void deleteRecord(int n) {
student object;
//open both files
ifstream file1;
file1.open("student.dat", ios::binary);
ofstream file2;
file2.open("Temp.dat", ios::out|ios::binary);
//write contents of f1 to f2
while (file1.read((char*)&object, sizeof(object))) {
if (object.studentNumber() != n)
file2.write((char*)&object, sizeof(object));
}
file1.close();
file2.close();
//delete original file and rename the new one
remove("student.dat");
rename("Temp.dat", "student.dat");
}
void editRecord(int n) {
fstream fp;
student object;
int found = 0;
fp.open("student.dat", ios::in | ios::out);
while (fp.read((char *)&object, sizeof(object)) && found == 0) {
if (object.studentNumber() == n) {
object.showData();
cout << "\nEnter The New Details of student";
object.getData();
int pos = -1 * sizeof(object);
fp.seekp(pos, ios::cur);
fp.write((char*)&object, sizeof(object));
found = 1;
}
//validation
if (object.studentNumber() != n) {
cout << "StudentID doesn't exist\n";
break;
}
}
fp.close();
}
int main() {
int n;
int studentIDNumber;
cout << " Press 1 if you choose to input student information\n Press 2 to display all student's information\n Press 3 to display a specific student's information\n Press 4 to modify student information\n Press 5 to delete a student\n";
cin >> n;
if (n == 1) {
write();
} else if(n == 2){
display();
}
else if (n == 3) {
cout << "Enter the Student ID to get the student information: ";
cin >> studentIDNumber;
search(studentIDNumber);
}
else if (n == 4) {
cout << "Enter the Student ID to modify the student information: ";
cin >> studentIDNumber;
editRecord(studentIDNumber);
}
else if (n == 5) {
deleteRecord(studentIDNumber);
cout << "The record has been deleted.\n";
}
else {
cout << "Error. The number is neither 1 or 2. Please try again. \n";
}
return 0;
}
The output:
Student ID: 55
Student Name: John Doe
Points: 6.36599e-314
GPA: 7.27464e+199
Press any key to continue . . .

Related

How to delete stored data in a text file?

The code below was modified based on my original one to fix an error thanks to #RemyLebeau.
It woks great but a new issue have showed up where when I want to delete a student data using option 4 from the menu, after entering their ID, it says their data is deleted but its not. And at the end of the console the message "error reading data from file", under the Standard Error Stream (cerr), keeps showing up. And all my tries to fix it failed.
error_display
//Project on Student Management
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
using namespace std;
struct Course
{
string courseName;
string grade;
string status;
};
class Student
{
int id;
int year;
float cgpa;
vector<Course> courses;
string academic_advisor;
public:
Student();
void getData();
void showData() const;
int getID() const { return id; }
friend ostream& operator<<(ostream &out, const Student &s);
friend istream& operator>>(istream &in, Student &s);
};
void writeStr(ostream &out, const string &str)
{
size_t size = str.size();
out.write((char*)&size, sizeof(size));
if (size)
out.write(str.c_str(), size);
}
void readStr(istream &in, string &str)
{
str.clear();
size_t size;
if (in.read((char*)&size, sizeof(size)))
{
if (size > 0)
{
str.resize(size);
in.read(&str[0], size);
}
}
}
ostream& operator<<(ostream &out, const Course &c)
{
writeStr(out, c.courseName);
writeStr(out, c.grade);
writeStr(out, c.status);
return out;
}
istream& operator>>(istream &in, Course &c)
{
readStr(in, c.courseName);
readStr(in, c.grade);
readStr(in, c.status);
return in;
}
ostream& operator<<(ostream &out, const Student &s)
{
out.write((char*)&s.id, sizeof(s.id));
out.write((char*)&s.year, sizeof(s.year));
out.write((char*)&s.cgpa, sizeof(s.cgpa));
writeStr(out, s.academic_advisor);
size_t NumberOfcourses = s.courses.size();
out.write((char*)&NumberOfcourses, sizeof(NumberOfcourses));
for(int i = 0; i < NumberOfcourses; ++i)
{
if (!(out << s.courses[i]))
break;
}
return out;
}
istream& operator>>(istream &in, Student &s)
{
s.courses.clear();
in.read((char*)&s.id, sizeof(s.id));
in.read((char*)&s.year, sizeof(s.year));
in.read((char*)&s.cgpa, sizeof(s.cgpa));
readStr(in, s.academic_advisor);
size_t NumberOfcourses;
if (in.read((char*)&NumberOfcourses, sizeof(NumberOfcourses)))
{
s.courses.reserve(NumberOfcourses);
Course c;
for(size_t i = 0; i < NumberOfcourses; ++i)
{
if (in >> c)
s.courses.push_back(c);
else
break;
}
}
return in;
}
Student::Student()
{
id = 0;
year = 0;
cgpa = 0.0f;
}
void Student::getData()
{
courses.clear();
cout << "\n\nEnter Student Details......\n";
cout << "Enter ID No. : "; cin >> id;
cout << "Enter Intake Year of the Student: "; cin >> year;
cout << "Enter number of Taken courses: ";
size_t NumberOfcourses;
cin >> NumberOfcourses;
cin.ignore();
courses.reserve(NumberOfcourses);
Course c;
for(int a = 0; a < NumberOfcourses; ++a)
{
cout << "\nEnter Subject Name: ";
getline(cin, c.courseName);
cout << "Enter Grade of Subject: ";
getline(cin, c.grade);
cout << "Enter Subject Status: ";
getline(cin, c.status);
courses.push_back(c);
}
cout << "Enter student CGPA: ";
cin >> cgpa;
cin.ignore();
cout << endl;
cout << "Enter Name of Academic Advisor of Student: ";
getline(cin, academic_advisor);
}
void Student::showData() const
{
cout << "\n\n.......Student Details......\n";
cout << "ID No. : " << id << endl;
cout << "Intake Year : " << year << endl;
cout << "Subjects Taken in Previous Semester : " << endl;
for(size_t t = 0; t < courses.size(); ++t)
{
cout << "\t" << courses[t].courseName << ": " << courses[t].grade << " (" << courses[t].status << ") ";
cout << endl;
}
cout << "CGPA : " << cgpa << endl;
cout << "Name of academic advisor of Student : " << academic_advisor << endl;
cout << endl;
}
void addData()
{
Student s;
s.getData();
ofstream fout("Students.txt", ios::binary|ios::app);
if (fout << s)
cout << "\n\nData Successfully Saved to File....\n";
else
cerr << "\n\nError Saving Data to File!\n";
}
void displayData()
{
ifstream fin("Students.txt", ios::binary);
Student s;
while (fin >> s)
{
s.showData();
}
if (fin)
cout << "\n\nData Reading from File Successfully Done....\n";
else
cerr << "\n\nError Reading Data from File!\n";
}
void searchData()
{
int n;
cout << "Enter ID Number you want to search for : ";
cin >> n;
ifstream fin("Students.txt", ios::binary);
Student s;
bool flag = false;
while (fin >> s)
{
if (n == s.getID())
{
cout << "The Details of ID No. " << n << " are: \n";
s.showData();
flag = true;
break;
}
}
if (fin)
{
if (!flag)
cout << "The ID No. " << n << " not found....\n\n";
cout << "\n\nData Reading from File Successfully Done....\n";
}
else
cerr << "\n\nError Reading Data from File!\n";
}
void deleteData()
{
int n;
cout << "Enter ID Number you want to delete : ";
cin >> n;
ifstream fin("Students.txt", ios::binary);
ofstream fout("TempStud.txt", ios::binary);
ofstream tout("TrashStud.txt", ios::binary|ios::app);
Student s;
bool flag = false;
while (fin >> s)
{
if (n == s.getID())
{
cout << "The Following ID No. " << n << " has been deleted:\n";
s.showData();
tout << s;
flag = true;
}
else
{
fout << s;
}
}
if (fin)
{
if (fout)
{
fin.close();
fout.close();
if (!flag)
{
cout << "The ID No. " << n << " not found....\n\n";
remove("tempStud.txt");
}
else
{
remove("Students.txt");
rename("tempStud.txt", "Students.txt");
cout << "\n\nData Successfully Deleted from File....\n";
}
}
else
{
cerr << "\n\nError Saving Data to File!\n";
}
}
else
{
cerr << "\n\nError Reading Data from File!\n";
}
}
void modifyData()
{
int n;
cout << "Enter ID Number you want to Modify : ";
cin >> n;
ifstream fin("Students.txt", ios::binary);
ofstream fout("TempStud.txt", ios::binary);
Student s;
bool flag = false;
while (fin >> s)
{
if (n == s.getID())
{
cout << "The Following ID No. " << n << " will be modified with new data:\n";
s.showData();
cout << "\n\nNow Enter the New Details....\n";
s.getData();
flag = true;
}
fout << s;
}
if (fin)
{
if (fout)
{
fin.close();
fout.close();
if (!flag)
{
cout << "The ID No. " << n << " not found....\n\n";
remove("TempStud.txt");
}
else
{
remove("Students.txt");
rename("TempStud.txt", "Students.txt");
cout << "\n\nData Successfully Updated in File....\n";
}
}
else
{
cerr << "\n\nError Saving Data to File!\n";
}
}
else
{
cerr << "\n\nError Reading Data from File!\n";
}
}
void project()
{
int ch;
do
{
system("cls");
cout << "...............STUDENT MANAGEMENT SYSTEM..............\n";
cout << "====================SEGI University=================\n";
cout << "0. Exit from Program\n";
cout << "1. Write Data to File\n";
cout << "2. Read Data From File\n";
cout << "3. Search Data From File\n";
cout << "4. Delete Data From File\n";
cout << "5. Modify Data in File\n";
cout << "Enter your choice : ";
cin >> ch;
system("cls");
switch (ch)
{
case 1: addData(); break;
case 2: displayData(); break;
case 3: searchData(); break;
case 4: deleteData(); break;
case 5: modifyData(); break;
}
system("pause");
}
while (ch != 0);
}
int main()
{
project();
}
The error is because fin ( in deleteData () function) runs till the end of file , and at the end fin stores nullptr(boolean conversion to false) that is why else statement runs.And its obvious that why the while loop breaks .
for checking if the file is open or not you can use if(fin.is_open()) for fin and similarly for fout like if(fout.is_open())

How to display all the data I entered into my text file?

The following is a code to enter some details of students into a text file and from the main menu, the user can display them using option 2.
My problem is in the section where it should display all the "Taken Courses by student".
When I choose to display all data, the "mentioned section using the for loop only display the last value I enter when writing to the file.
How can I make it display all my entries?
The issue is under the showdata and displaydata functions.
//Project on Student Management
#include<iostream>
#include<fstream>
#include<iomanip>
#include<stdlib.h>
using namespace std;
class Student
{
int id;
int year;
char grade[50];
float cgpa;
int NumberOfcourses;
char courseName[100];
char academic_advisor[100];
char status[100];
public:
void getData();
void showData();
int getID(){return id;}
}s;
void Student::getData()
{
cout<<"\n\nEnter Student Details......\n";
cout<<"Enter ID No. : "; cin>>id;
cout << "Enter Intake Year of the Student: "; cin >> year;
cout << "Enter number of Taken courses: ";
cin >> NumberOfcourses;
for(int a=1; a<=s.NumberOfcourses; a++)
{
cout<<"\nEnter Subject Name: ";
cin.ignore();
cin.getline(courseName, 100);
cout << "Enter Grade of Subject: ";
cin >> grade;
cout<<"\nEnter Subject Status: ";
cin.ignore();
cin.getline(status, 100);
}
cout << "Enter student CGPA: ";
cin >> s.cgpa;
cout << endl;
cout << "Enter Name of Academic Advisor of Student: "; cin.ignore();
cin.getline(s.academic_advisor, 100);
}
void Student::showData()
{
cout << "\n\n.......Student Details......\n";
cout << "ID No. : " << id << endl;
cout << "Intake Year : " << year << endl;
cout << "Subjects Taken in Previous Semester : " << endl;
for(int t=1; t<=NumberOfcourses; t++)
{
cout << "\t" << courseName << ": " << grade << " ("<< status << ") ";
cout << endl;
}
cout << "CGPA : " << cgpa << endl;
cout << "Name of academic advisor of Student : " << academic_advisor << endl;
cout << endl;
}
void addData()
{
ofstream fout;
fout.open("Students.txt", ios::out|ios::app);
s.getData();
fout.write((char*)&s,sizeof(s));
fout.close();
cout<<"\n\nData Successfully Saved to File....\n";
}
void displayData()
{
ifstream fin;
fin.open("Students.txt",ios::in);
while(fin.read((char*)&s,sizeof(s)))
{
s.showData();
}
fin.close();
cout<<"\n\nData Reading from File Successfully Done....\n";
}
void searchData()
{
int n, flag=0;
ifstream fin;
fin.open("Students.txt",ios::in);
cout<<"Enter ID Number you want to search for : ";
cin>>n;
while(fin.read((char*)&s,sizeof(s)))
{
if(n==s.getID())
{
cout<<"The Details of ID No. "<<n<<" are: \n";
s.showData();
flag++;
}
}
fin.close();
if(flag==0)
cout<<"The ID No. "<<n<<" not found....\n\n";
cout<<"\n\nData Reading from File Successfully Done....\n";
}
void deleteData()
{
int n, flag=0;
ifstream fin;
ofstream fout,tout;
fin.open("Students.txt",ios::in);
fout.open("TempStud.txt",ios::out|ios::app);
tout.open("TrashStud.txt",ios::out|ios::app);
cout<<"Enter ID Number you want to delete : ";
cin>>n;
while(fin.read((char*)&s,sizeof(s)))
{
if(n==s.getID())
{
cout<<"The Following ID No. "<< n <<" has been deleted:\n";
s.showData();
tout.write((char*)&s,sizeof(s));
flag++;
}
else
{
fout.write((char*)&s,sizeof(s));
}
}
fout.close();
tout.close();
fin.close();
if(flag==0)
cout<<"The ID No. "<< n <<" not found....\n\n";
remove("Students.dat");
rename("tempStud.txt","Students.txt");
}
void modifyData()
{
int n, flag=0, pos;
fstream fio;
fio.open("Students.txt", ios::in|ios::out);
cout<<"Enter ID Number you want to Modify : ";
cin>>n;
while(fio.read((char*)&s,sizeof(s)))
{
pos=fio.tellg();
if(n==s.getID())
{
cout<<"The Following ID No. "<<n<<" will be modified with new data:\n";
s.showData();
cout<<"\n\nNow Enter the New Details....\n";
s.getData();
fio.seekg(pos-sizeof(s));
fio.write((char*)&s,sizeof(s));
flag++;
}
}
fio.close();
if(flag==0)
cout<<"The ID No. "<<n<<" not found....\n\n";
}
void project()
{
int ch;
do
{
system("cls");
cout<<"...............STUDENT MANAGEMENT SYSTEM..............\n";
cout<<"======================================================\n";
cout<<"0. Exit from Program\n";
cout<<"1. Write Data to File\n";
cout<<"2. Read Data From File\n";
cout<<"3. Search Data From File\n";
cout<<"4. Delete Data From File\n";
cout<<"5. Modify Data in File\n";
cout<<"Enter your choice : ";
cin>>ch;
system("cls");
switch(ch)
{
case 1: addData(); break;
case 2: displayData(); break;
case 3: searchData(); break;
case 4: deleteData(); break;
case 5: modifyData(); break;
}
system("pause");
}while(ch);
}
int main()
{
project();
}
Console Display with problem
Your Student class can only hold 1 set of course information. Your getData() loop is overwriting the same variables over and over, that is why you only see the last course entered. You need to allocate an array (or better, use a std::vector) to hold multiple courses per Student.
There are other problems with your code as well.
Try something more like this instead:
//Project on Student Management
#include <iostream>
#include <fstream>
using namespace std;
struct Course
{
char courseName[100];
char grade[50];
char status[100];
};
class Student
{
int id;
int year;
float cgpa;
int NumberOfcourses;
Course *courses;
char academic_advisor[100];
public:
Student();
~Student();
void getData();
void showData() const;
int getID() const { return id; }
friend ostream& operator<<(ostream &out, const Student &s);
friend istream& operator>>(istream &in, Student &s);
};
ostream& operator<<(ostream &out, const Course &c)
{
out.write(c.courseName, sizeof(c.courseName));
out.write(c.grade, sizeof(c.grade));
out.write(c.status, sizeof(c.status));
return out;
}
istream& operator>>(istream &in, Course &c)
{
in.read(c.courseName, sizeof(c.courseName));
in.read(c.grade, sizeof(c.grade));
in.read(c.status, sizeof(c.status));
return in;
}
ostream& operator<<(ostream &out, const Student &s)
{
out.write((char*)&s.id, sizeof(s.id));
out.write((char*)&s.year, sizeof(s.year));
out.write((char*)&s.cgpa, sizeof(s.cgpa));
out.write(s.academic_advisor, sizeof(s.academic_advisor));
out.write((char*)&s.NumberOfcourses, sizeof(s.NumberOfcourses));
for(int i = 0; i < s.NumberOfcourses; ++i)
{
out << s.courses[i];
}
return out;
}
istream& operator>>(istream &in, Student &s)
{
delete[] s.courses;
s.courses = NULL;
s.NumberOfcourses = 0;
in.read((char*)&s.id, sizeof(s.id));
in.read((char*)&s.year, sizeof(s.year));
in.read((char*)&s.cgpa, sizeof(s.cgpa));
in.read(s.academic_advisor, sizeof(s.academic_advisor));
int NumberOfcourses;
if (in.read((char*)&NumberOfcourses, sizeof(NumberOfcourses)))
{
s.courses = new Course[NumberOfcourses];
for(int i = 0; i < NumberOfcourses; ++i)
{
if (in >> s.courses[i])
s.NumberOfcourses++;
else
break;
}
}
return in;
}
Student::Student()
{
id = 0;
year = 0;
cgpa = 0.0f;
NumberOfcourses = 0;
courses = NULL;
academic_advisor[0] = '\0';
}
Student::~Student()
{
delete[] courses;
}
void Student::getData()
{
cout << "\n\nEnter Student Details......\n";
cout << "Enter ID No. : "; cin >> id;
cout << "Enter Intake Year of the Student: "; cin >> year;
cout << "Enter number of Taken courses: ";
cin >> NumberOfcourses;
cin.ignore();
delete[] courses;
courses = new Course[NumberOfcourses];
for(int a = 0; a < NumberOfcourses; ++a)
{
cout << "\nEnter Subject Name: ";
cin.getline(courses[a].courseName, 100);
cout << "Enter Grade of Subject: ";
cin.getline(courses[a].grade, 50);
cout << "\nEnter Subject Status: ";
cin.getline(courses[a].status, 100);
}
cout << "Enter student CGPA: ";
cin >> cgpa;
cin.ignore();
cout << endl;
cout << "Enter Name of Academic Advisor of Student: ";
cin.getline(academic_advisor, 100);
}
void Student::showData() const
{
cout << "\n\n.......Student Details......\n";
cout << "ID No. : " << id << endl;
cout << "Intake Year : " << year << endl;
cout << "Subjects Taken in Previous Semester : " << endl;
for(int t = 0; t < NumberOfcourses; ++t)
{
cout << "\t" << courses[t].courseName << ": " << courses[t].grade << " (" << courses[t].status << ") ";
cout << endl;
}
cout << "CGPA : " << cgpa << endl;
cout << "Name of academic advisor of Student : " << academic_advisor << endl;
cout << endl;
}
void addData()
{
Student s;
s.getData();
ofstream fout("Students.txt", ios::binary|ios::app);
if (fout << s)
cout << "\n\nData Successfully Saved to File....\n";
else
cerr << "\n\nError Saving Data to File!\n";
}
void displayData()
{
ifstream fin("Students.txt", ios::binary);
Student s;
while (fin >> s)
{
s.showData();
}
if (!fin)
cerr << "\n\nError Reading Data from File!\n";
else
cout << "\n\nData Reading from File Successfully Done....\n";
}
void searchData()
{
int n;
cout << "Enter ID Number you want to search for : ";
cin >> n;
ifstream fin("Students.txt", ios::binary);
Student s;
bool flag = false;
while (fin >> s)
{
if (n == s.getID())
{
cout << "The Details of ID No. " << n << " are: \n";
s.showData();
flag = true;
break;
}
}
if (!fin)
{
cerr << "\n\nError Reading Data from File!\n";
}
else
{
if (!flag)
cout << "The ID No. " << n << " not found....\n\n";
cout << "\n\nData Reading from File Successfully Done....\n";
}
}
void deleteData()
{
int n;
cout << "Enter ID Number you want to delete : ";
cin >> n;
ifstream fin("Students.txt", ios::binary);
ofstream fout("TempStud.txt", ios::binary);
ofstream tout("TrashStud.txt", ios::binary|ios::app);
Student s;
bool flag = false;
while (fin >> s)
{
if (n == s.getID())
{
cout << "The Following ID No. " << n << " will be deleted:\n";
s.showData();
tout << s;
flag = true;
}
else
{
fout << s;
}
}
if (!fin)
{
cerr << "\n\nError Reading Data from File!\n";
}
else if (!fout)
{
cerr << "\n\nError Saving Data to File!\n";
}
else
{
fin.close();
fout.close();
if (!flag)
{
cout << "The ID No. " << n << " not found....\n\n";
remove("tempStud.txt");
}
else
{
remove("Students.txt");
rename("tempStud.txt", "Students.txt");
cout << "\n\nData Successfully Deleted from File....\n";
}
}
}
void modifyData()
{
int n;
cout << "Enter ID Number you want to Modify : ";
cin >> n;
ifstream fin("Students.txt", ios::binary);
ofstream fout("TempStud.txt", ios::binary);
Student s;
bool flag = false;
while (fin >> s)
{
if (n == s.getID())
{
cout << "The Following ID No. " << n << " will be modified with new data:\n";
s.showData();
cout << "\n\nNow Enter the New Details....\n";
s.getData();
flag = true;
}
fout << s;
}
if (!fin)
{
cerr << "\n\nError Reading Data from File!\n";
}
else if (!fout)
{
cerr << "\n\nError Saving Data to File!\n";
}
else
{
fin.close();
fout.close();
if (!flag)
{
cout << "The ID No. " << n << " not found....\n\n";
remove("TempStud.txt");
}
else
{
remove("Students.txt");
rename("TempStud.txt", "Students.txt");
cout << "\n\nData Successfully Updated in File....\n";
}
}
}
void project()
{
int ch;
do
{
system("cls");
cout << "...............STUDENT MANAGEMENT SYSTEM..............\n";
cout << "======================================================\n";
cout << "0. Exit from Program\n";
cout << "1. Write Data to File\n";
cout << "2. Read Data From File\n";
cout << "3. Search Data From File\n";
cout << "4. Delete Data From File\n";
cout << "5. Modify Data in File\n";
cout << "Enter your choice : ";
cin >> ch;
system("cls");
switch (ch)
{
case 1: addData(); break;
case 2: displayData(); break;
case 3: searchData(); break;
case 4: deleteData(); break;
case 5: modifyData(); break;
}
system("pause");
}
while (ch != 0);
}
int main()
{
project();
}
Alternatively:
//Project on Student Management
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
using namespace std;
struct Course
{
string courseName;
string grade;
string status;
};
class Student
{
int id;
int year;
float cgpa;
vector<Course> courses;
string academic_advisor;
public:
Student();
void getData();
void showData() const;
int getID() const { return id; }
friend ostream& operator<<(ostream &out, const Student &s);
friend istream& operator>>(istream &in, Student &s);
};
void writeStr(ostream &out, const string &str)
{
size_t size = str.size();
out.write((char*)&size, sizeof(size));
if (size)
out.write(str.c_str(), size);
}
void readStr(istream &in, string &str)
{
str.clear();
size_t size;
if (in.read((char*)&size, sizeof(size)))
{
if (size > 0)
{
str.resize(size);
in.read(&str[0], size);
}
}
}
ostream& operator<<(ostream &out, const Course &c)
{
writeStr(out, c.courseName);
writeStr(out, c.grade);
writeStr(out, c.status);
return out;
}
istream& operator>>(istream &in, Course &c)
{
readStr(in, c.courseName);
readStr(in, c.grade);
readStr(in, c.status);
return in;
}
ostream& operator<<(ostream &out, const Student &s)
{
out.write((char*)&s.id, sizeof(s.id));
out.write((char*)&s.year, sizeof(s.year));
out.write((char*)&s.cgpa, sizeof(s.cgpa));
writeStr(out, s.academic_advisor);
size_t NumberOfcourses = s.courses.size();
out.write((char*)&NumberOfcourses, sizeof(NumberOfcourses));
for(int i = 0; i < NumberOfcourses; ++i)
{
if (!(out << s.courses[i]))
break;
}
return out;
}
istream& operator>>(istream &in, Student &s)
{
s.courses.clear();
in.read((char*)&s.id, sizeof(s.id));
in.read((char*)&s.year, sizeof(s.year));
in.read((char*)&s.cgpa, sizeof(s.cgpa));
readStr(in, s.academic_advisor);
size_t NumberOfcourses;
if (in.read((char*)&NumberOfcourses, sizeof(NumberOfcourses)))
{
s.courses.reserve(NumberOfcourses);
Course c;
for(size_t i = 0; i < NumberOfcourses; ++i)
{
if (in >> c)
s.courses.push_back(c);
else
break;
}
}
return in;
}
Student::Student()
{
id = 0;
year = 0;
cgpa = 0.0f;
}
void Student::getData()
{
courses.clear();
cout << "\n\nEnter Student Details......\n";
cout << "Enter ID No. : "; cin >> id;
cout << "Enter Intake Year of the Student: "; cin >> year;
cout << "Enter number of Taken courses: ";
size_t NumberOfcourses;
cin >> NumberOfcourses;
cin.ignore();
courses.reserve(NumberOfcourses);
Course c;
for(int a = 0; a < NumberOfcourses; ++a)
{
cout << "\nEnter Subject Name: ";
getline(cin, c.courseName);
cout << "Enter Grade of Subject: ";
getline(cin, c.grade);
cout << "\nEnter Subject Status: ";
getline(cin, c.status);
s.courses.push_back(c);
}
cout << "Enter student CGPA: ";
cin >> cgpa;
cin.ignore();
cout << endl;
cout << "Enter Name of Academic Advisor of Student: ";
getline(cin, academic_advisor);
}
void Student::showData() const
{
cout << "\n\n.......Student Details......\n";
cout << "ID No. : " << id << endl;
cout << "Intake Year : " << year << endl;
cout << "Subjects Taken in Previous Semester : " << endl;
for(size_t t = 0; t < courses.size(); ++t)
{
cout << "\t" << courses[t].courseName << ": " << courses[t].grade << " (" << courses[t].status << ") ";
cout << endl;
}
cout << "CGPA : " << cgpa << endl;
cout << "Name of academic advisor of Student : " << academic_advisor << endl;
cout << endl;
}
void addData()
{
Student s;
s.getData();
ofstream fout("Students.txt", ios::binary|ios::app);
if (fout << s)
cout << "\n\nData Successfully Saved to File....\n";
else
cerr << "\n\nError Saving Data to File!\n";
}
void displayData()
{
ifstream fin("Students.txt", ios::binary);
Student s;
while (fin >> s)
{
s.showData();
}
if (!fin)
cerr << "\n\nError Reading Data from File!\n";
else
cout << "\n\nData Reading from File Successfully Done....\n";
}
void searchData()
{
int n;
cout << "Enter ID Number you want to search for : ";
cin >> n;
ifstream fin("Students.txt", ios::binary);
Student s;
bool flag = false;
while (fin >> s)
{
if (n == s.getID())
{
cout << "The Details of ID No. " << n << " are: \n";
s.showData();
flag = true;
break;
}
}
if (!fin)
{
cerr << "\n\nError Reading Data from File!\n";
}
else
{
if (!flag)
cout << "The ID No. " << n << " not found....\n\n";
cout << "\n\nData Reading from File Successfully Done....\n";
}
}
void deleteData()
{
int n;
cout << "Enter ID Number you want to delete : ";
cin >> n;
ifstream fin("Students.txt", ios::binary);
ofstream fout("TempStud.txt", ios::binary);
ofstream tout("TrashStud.txt", ios::binary|ios::app);
Student s;
bool flag = false;
while (fin >> s)
{
if (n == s.getID())
{
cout << "The Following ID No. " << n << " will be deleted:\n";
s.showData();
tout << s;
flag = true;
}
else
{
fout << s;
}
}
if (!fin)
{
cerr << "\n\nError Reading Data from File!\n";
}
else if (!fout)
{
cerr << "\n\nError Saving Data to File!\n";
}
else
{
fin.close();
fout.close();
if (!flag)
{
cout << "The ID No. " << n << " not found....\n\n";
remove("tempStud.txt");
}
else
{
remove("Students.txt");
rename("tempStud.txt", "Students.txt");
cout << "\n\nData Successfully Deleted from File....\n";
}
}
}
void modifyData()
{
int n;
cout << "Enter ID Number you want to Modify : ";
cin >> n;
ifstream fin("Students.txt", ios::binary);
ofstream fout("TempStud.txt", ios::binary);
Student s;
bool flag = false;
while (fin >> s)
{
if (n == s.getID())
{
cout << "The Following ID No. " << n << " will be modified with new data:\n";
s.showData();
cout << "\n\nNow Enter the New Details....\n";
s.getData();
flag = true;
}
fout << s;
}
if (!fin)
{
cerr << "\n\nError Reading Data from File!\n";
}
else if (!fout)
{
cerr << "\n\nError Saving Data to File!\n";
}
else
{
fin.close();
fout.close();
if (!flag)
{
cout << "The ID No. " << n << " not found....\n\n";
remove("TempStud.txt");
}
else
{
remove("Students.txt");
rename("TempStud.txt", "Students.txt");
cout << "\n\nData Successfully Updated in File....\n";
}
}
}
void project()
{
int ch;
do
{
system("cls");
cout << "...............STUDENT MANAGEMENT SYSTEM..............\n";
cout << "======================================================\n";
cout << "0. Exit from Program\n";
cout << "1. Write Data to File\n";
cout << "2. Read Data From File\n";
cout << "3. Search Data From File\n";
cout << "4. Delete Data From File\n";
cout << "5. Modify Data in File\n";
cout << "Enter your choice : ";
cin >> ch;
system("cls");
switch (ch)
{
case 1: addData(); break;
case 2: displayData(); break;
case 3: searchData(); break;
case 4: deleteData(); break;
case 5: modifyData(); break;
}
system("pause");
}
while (ch != 0);
}
int main()
{
project();
}

Need help resolving an Unhandled Exception Error

I've been learning to program for a few months now and I've been working on a program to manage student data. Here's the code:
#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
#include <stdio.h>
using namespace std;
class Student
{
private:
string name;
string course;
int section;
int grade;
public:
void calcgrade();
void getData();
void showData();
};
void Student::calcgrade()
{
if (grade >= 90)
grade = 'A';
else if (grade >= 80)
grade = 'B';
else if (grade >= 70)
grade = 'C';
else if (grade >= 60)
grade = 'D';
else
grade = 'F';
}
void Student::getData()
{
cout << "Enter the name of the student: ";
cin.ignore();
getline(cin, name);
cout << "Enter the course: ";
cin >> course;
cout << "Enter the section: ";
cin >> section;
cout << "Enter the grade received: ";
cin >> grade;
calcgrade();
}
void Student::showData()
{
cout << ".......Student Information......" << endl;
cout << "Student Name: " << name << endl;
cout << "Course: " << course << endl;
cout << "Section: " << section << endl;
cout << "Grade: " << grade << endl;
cout << endl;
}
void addData()
{
Student st;
ofstream fout;
fout.open("Student.data", ios::binary | ios::out |
ios::app);
st.getData();
fout.write((char*)& st, sizeof(st));
fout.close();
cout << "Data Successfully Saved to File." << endl;
}
void displayData()
{
Student st;
ifstream file;
file.open("Student.data", ios::in | ios::binary);
if (file.is_open())
{
while (file.read((char*)& st, sizeof(st)))
{
st.showData();
}
cout << "Finished Reading Data From File." <<
endl;
}
else
{
cout << "Unable to open file" << endl;
}
file.close();
}
void searchData()
{
Student st;
ifstream file;
file.open("Student.data", ios::in | ios::binary);
string search;
cout << "Please enter the first name of a student to search for: ";
cin >> search;
bool isFound = 0;
while (file.read((char*)& st, sizeof(st)))
{
string temp = " ";
getline(file, temp);
for (int i = 0; i < search.size(); i++)
{
if (temp[i] == search[i])
isFound = 1;
else
{
isFound = 0;
break;
}
}
if (isFound)
{
cout << "The name " << search << " was found in the database." << endl;
break;
}
}
if (file.read((char*)& st, sizeof(st)) && (!isFound))
{
cout << "Name not found." << endl;
}
file.close();
}
void modifyData()
{
Student st;
string stname;
bool isFound = 0;
int pos;
fstream file;
file.open("Student.data", ios::in | ios::out | ios::binary);
cout << "Enter the name of a student whose data you want to modify: ";
cin >> stname;
while (file.read((char*)& st, sizeof(st)))
{
string temp = " ";
getline(file, temp);
for (int i = 0; i < stname.size(); i++)
{
if (temp[i] == stname[i])
isFound = 1;
else
{
isFound = 0;
break;
}
}
if (isFound)
{
pos = file.tellg();
cout << "Current Data" << endl;
st.showData();
cout << "Modified Data" << endl;
st.getData();
file.seekg(pos - sizeof(st));
file.write((char*)& st, sizeof(st));
}
}
if (file.read((char*)& st, sizeof(st)) && (!isFound))
{
cout << "Name not found." << endl;
}
file.close();
}
void deleteData()
{
Student st;
string stname;
bool isFound = 0;
ifstream file;
ofstream fout;
file.open("Student.data", ios::in | ios::binary);
fout.open("Temporary.data", ios::out | ios::app | ios::binary);
cout << "Enter the name of a student whose data you want to delete: ";
cin >> stname;
while (file.read((char*)& st, sizeof(st)))
{
string temp = " ";
getline(file, temp);
for (int i = 0; i < stname.size(); i++)
{
if (temp[i] == stname[i])
isFound = 1;
else
{
isFound = 0;
break;
}
}
if (isFound)
{
cout << "Bleh" << endl;
fout.write((char*)& st, sizeof(st));
}
}
if (file.read((char*)& st, sizeof(st)) && (!isFound))
{
cout << "Name not found." << endl;
}
fout.close();
file.close();
remove("Student.data");
rename("Temporary.data", "Student.data");
}
void printData()
{
ifstream file;
file.open("Student.data", ios::in | ios::binary);
if (file.is_open())
{
cout << file.rdbuf();
}
file.close();
}
int main()
{
int num;
do
{
cout << "...............STUDENT MANAGEMENT SYSTEM..............\n";
cout << "======================================== ==============\n";
cout << "0. Close Program. " << endl;
cout << "1. Add Data. " << endl;
cout << "2. List Data. " << endl;
cout << "3. Modify Data. " << endl;
cout << "4. Search For Data. " << endl;
cout << "5. Print Data. " << endl;
cout << "6. Delete Data. " << endl;
cout << "Choose an option: ";
cin >> num;
if (num == 1)
{
addData();
}
else if (num == 2)
{
displayData();
}
else if (num == 3)
{
modifyData();
}
else if (num == 4)
{
searchData();
}
else if (num == 5)
{
printData();
}
else if (num == 6)
{
deleteData();
}
} while (num > 0);
return 0;
}
Ideally, when the program runs, the user chooses an option, with different function calls depending on the number entered. The Add Data option works fine, but when choosing others, such as List Data or Search Data, I run into an error such as: Unhandled exception thrown: read access violation. _Pnext was 0x10A6A04.
Code in xmemory:
inline void _Container_base12::_Orphan_all() noexcept {
#if _ITERATOR_DEBUG_LEVEL == 2
if (_Myproxy != nullptr) { // proxy allocated, drain it
_Lockit _Lock(_LOCK_DEBUG);
for (_Iterator_base12** _Pnext = &_Myproxy->_Myfirstiter; *_Pnext != nullptr;
*_Pnext = (*_Pnext)->_Mynextiter) {
(*_Pnext)->_Myproxy = nullptr;
}
_Myproxy->_Myfirstiter = nullptr;
}
Given there are no obvious errors in the code, I'd like a little help in figuring out what I've done wrong.

Customer Account banking system error with variable input

Im building a banking system. in my create_account it asks for account address and phone number as well as other questions. When I go to my Show account info (balance inquiry) I notice its not getting the right address as well as phone number. its showing "garbage". Im not sure whats going on If you can point me in the right direction and help out that would be appreciated.
/********************************************************************
* Vincent Dotts 09/29/2014 ch11.cpp *
* This program serves as a customer banking system *
*****************************HISTORY*********************************
* WHO DATE Discription *
*********************************************************************
* VD 09/30/2013 Created program *
********************************************************************/
#include<iostream>
#include<fstream>
#include<cctype>
#include<iomanip>
using namespace std;
class account
{
int accno;
double phone;
char name[30], address[40];
int deposit;
char type;
public:
void create_account(); //function to get data from user
void show_account() const; //function to show data on screen
void modify(); //function to add new data
void dep(int); //function to accept amount and add to balance amount
void draw(int); //function to accept amount and subtract from balance amount
void report() const; //function to show data in tabular format
int retacno() const; //function to return account number
int retdeposit() const; //function to return balance amount
char rettype() const; //function to return type of account
//int validate(int*); //prototype for function for validation
};
void account::create_account()
{
cout << "\nEnter The account # (5 digits): ";
cin >> accno;
while (accno < 10000 || accno > 99999)
{
cout << "Invalid Account # Please reenter";
cin >> accno;
}
cout << "\n\nEnter The Name of The account Holder : ";
cin.ignore();
cin.getline(name, 30);
cout << "\n\nEnter Address of The account Holder: "<<endl;
cout << "Example: 18 First St, Oakland, CA 97836" <<endl;
cin.ignore();
cin.getline(address, 40);
cout << "\nEnter Phone Number: ";
cin >> phone;
while (phone<1000000000 || phone>9999999999)
{
cout << "Invalid Phone # Please reenter";
cin >> phone;
}
cout << "\nEnter Type of The account (C/S) : ";
cin >> type;
type = toupper(type);
cout << "\nEnter The Initial amount(>=500 for Saving and >=1000 for current ) : ";
cin >> deposit;
cout << "\n\n\nAccount Created..";
}
void account::show_account() const
{
cout << "\nAccount No. : " << accno;
cout << "\nAccount Holder Name: " << name;
cout << "\nAccount Holder Address:" << address;
cout << "\nAccount Holder Phone #:" << phone;
cout << "\nType of Account : " << type;
cout << "\nBalance amount : " << deposit;
}
void account::modify()
{
cout << "\nAccount No. : " << accno;
cout << "\nModify Account Holder Name: ";
cin.ignore();
cin.getline(name, 30);
cout << "\nModify Account Holder Address: " << endl;
cout << "Example: 18 First St, Oakland, CA 97836";
cin.ignore();
cin.getline(address, 60);
cout << "\nModify Account Holder Phone Number: ";
cin >> phone;
cout << "\nModify Type of Account: ";
cin >> type;
type = toupper(type);
cout << "\nModify Balance amount: ";
cin >> deposit;
}
void account::dep(int x)
{
deposit += x;
}
void account::draw(int x)
{
deposit -= x;
}
void account::report() const
{
cout << accno <<" " << name << " " << address<<" "<< phone << " " << type << " " << deposit << endl;
}
int account::retacno() const
{
return accno;
}
int account::retdeposit() const
{
return deposit;
}
char account::rettype() const
{
return type;
}
// function declaration
void write_account(); //function to write record in binary file
void display_sp(int); //function to display account details given by user
void modify_account(int); //function to modify record of file
void delete_account(int); //function to delete record of file
void display_all(); //function to display all account details
void deposit_withdraw(int, int); // function to desposit/withdraw amount for given account
void intro(); //introductory screen function
// THE MAIN FUNCTION OF PROGRAM
int main()
{
char ch;
int num;
intro();
do
{
system("cls");
cout << "\n\n\n\tMAIN MENU";
cout << "\n\n\t01. NEW ACCOUNT";
cout << "\n\n\t02. DEPOSIT AMOUNT";
cout << "\n\n\t03. WITHDRAW AMOUNT";
cout << "\n\n\t04. BALANCE ENQUIRY";
cout << "\n\n\t05. ALL ACCOUNT HOLDER LIST";
cout << "\n\n\t06. CLOSE AN ACCOUNT";
cout << "\n\n\t07. MODIFY AN ACCOUNT";
cout << "\n\n\t08. EXIT";
cout << "\n\n\tSelect Your Option (1-8) ";
cin >> ch;
system("cls");
switch (ch)
{
case '1':
write_account();
break;
case '2':
cout << "\n\n\tEnter The account No. : "; cin >> num;
deposit_withdraw(num, 1);
break;
case '3':
cout << "\n\n\tEnter The account No. : "; cin >> num;
deposit_withdraw(num, 2);
break;
case '4':
cout << "\n\n\tEnter The account No. : "; cin >> num;
display_sp(num);
break;
case '5':
display_all();
break;
case '6':
cout << "\n\n\tEnter The account No. : "; cin >> num;
delete_account(num);
break;
case '7':
cout << "\n\n\tEnter The account No. : "; cin >> num;
modify_account(num);
break;
case '8':
cout << "\n\n\tThank you Come Again";
break;
default:cout << "\a";
}
cin.ignore();
cin.get();
} while (ch != '8');
return 0;
}
// function to write in file
void write_account()
{
account ac;
ofstream outFile;
outFile.open("account.dat", ios::binary | ios::app);
ac.create_account();
outFile.write(reinterpret_cast<char *> (&ac), sizeof(account));
outFile.close();
}
// function to read specific record from file
void display_sp(int n)
{
account ac;
bool flag = false;
ifstream inFile;
inFile.open("account.dat", ios::binary);
if (!inFile)
{
cout << "File could not be open !! Press any Key...";
return;
}
cout << "\nBALANCE DETAILS\n";
while (inFile.read(reinterpret_cast<char *> (&ac), sizeof(account)))
{
if (ac.retacno() == n)
{
ac.show_account();
flag = true;
}
}
inFile.close();
if (flag == false)
cout << "\n\nAccount number does not exist";
}
// function to modify record of file
void modify_account(int n)
{
bool found = false;
account ac;
fstream File;
File.open("account.dat", ios::binary | ios::in | ios::out);
if (!File)
{
cout << "File could not be open !! Press any Key...";
return;
}
while (!File.eof() && found == false)
{
File.read(reinterpret_cast<char *> (&ac), sizeof(account));
if (ac.retacno() == n)
{
ac.show_account();
cout << "\n\nEnter The New Details of account" << endl;
ac.modify();
int pos = (-1)*static_cast<int>(sizeof(account));
File.seekp(pos, ios::cur);
File.write(reinterpret_cast<char *> (&ac), sizeof(account));
cout << "\n\n\t Record Updated";
found = true;
}
}
File.close();
if (found == false)
cout << "\n\n Record Not Found ";
}
// function to delete record of file
void delete_account(int n)
{
account ac;
ifstream inFile;
ofstream outFile;
inFile.open("account.dat", ios::binary);
if (!inFile)
{
cout << "File could not be open !! Press any Key...";
return;
}
outFile.open("Temp.dat", ios::binary);
inFile.seekg(0, ios::beg);
while (inFile.read(reinterpret_cast<char *> (&ac), sizeof(account)))
{
if (ac.retacno() != n)
{
outFile.write(reinterpret_cast<char *> (&ac), sizeof(account));
}
}
inFile.close();
outFile.close();
remove("account.dat");
rename("Temp.dat", "account.dat");
cout << "\n\n\tRecord Deleted ..";
}
// function to display all accounts deposit list
void display_all()
{
account ac;
ifstream inFile;
inFile.open("account.dat", ios::binary);
if (!inFile)
{
cout << "File could not be open !! Press any Key...";
return;
}
cout << "\n\n\t\tACCOUNT HOLDER LIST\n\n";
cout << "*********************************************************************\n";
cout << "A/c# NAME Address Phone # Type Balance\n";
cout << "*********************************************************************\n";
while (inFile.read(reinterpret_cast<char *> (&ac), sizeof(account)))
{
ac.report();
}
inFile.close();
}
// function to deposit and withdraw amounts
void deposit_withdraw(int n, int option)
{
int amt;
bool found = false;
account ac;
fstream File;
File.open("account.dat", ios::binary | ios::in | ios::out);
if (!File)
{
cout << "File could not be open !! Press any Key...";
return;
}
while (!File.eof() && found == false)
{
File.read(reinterpret_cast<char *> (&ac), sizeof(account));
if (ac.retacno() == n)
{
ac.show_account();
if (option == 1)
{
cout << "\n\n\tTO DEPOSITE AMOUNT ";
cout << "\n\nEnter The amount to be deposited";
cin >> amt;
ac.dep(amt);
}
if (option == 2)
{
cout << "\n\n\tTO WITHDRAW AMOUNT ";
cout << "\n\nEnter The amount to be withdraw";
cin >> amt;
int bal = ac.retdeposit() - amt;
if ((bal<500 && ac.rettype() == 'S') || (bal<1000 && ac.rettype() == 'C'))
cout << "Insufficience balance";
else
ac.draw(amt);
}
int pos = (-1)*static_cast<int>(sizeof(ac));
File.seekp(pos, ios::cur);
File.write(reinterpret_cast<char *> (&ac), sizeof(account));
cout << "\n\n\t Record Updated";
found = true;
}
}
File.close();
if (found == false)
cout << "\n\n Record Not Found ";
}
// INTRODUCTION FUNCTION
void intro()
{
cout << "\n\n\n\t CUSTOMER";
cout << "\n\n\t ACCOUNT";
cout << "\n\n\t SYSTEM";
cin.get();
}
http://imgur.com/kV8w5KB
a screen shot of my input

Deleting a record from text file

I have got an assignment project to make a program using C++ which maintains a list of Students (their name, age, and GPA) in a text file. The program has the following functionality:
Insertion of record
Deletion of record
Searching of record
Updating a record
When deleting a record my code takes a string name as input and removes it from the text file. However the next two lines in the file (age & gpa for that student) are left. How do I remove those too?
Following is the code for my program.
#include <iostream>
#include <fstream>
using namespace std;
void writing();
void deleting();
void searching();
class student {
public:
int age = 0;
string name;
void SetGpa(float x)
{
gpa = x;
}
float GetGpa()
{
return gpa;
}
private:
float gpa = 0.0;
};
int main()
{
int opt;
cout << "Please Enter an option number to continue:\n ";
cout << "\nPress 1 for New Record insertion";
cout << "\nPress 2 for Record Deletion";
cout << "\nPress 3 for Searching a Record";
cout << "\nPress 4 for Updating a Record";
cout << "\nEnter option Number: ";
cin >> opt;
switch (opt)
{
case 1:
{
writing();
break;
}
case 2:
{
deleting();
break;
}
case 3:
{
searching();
break;
}
case 4:
{
deleting();
writing();
cout << "Record has been updated! ";
break;
}
}
}
void writing()
{
float a;
student moiz;
cout << "Please enter name of student: ";
cin >> moiz.name;
cout << "Please enter the age of student: ";
cin >> moiz.age;
cout << "Pleae enter the Gpa of student: ";
cin >> a;
moiz.SetGpa(a);
ofstream myfile;
myfile.open("record.txt", ios::app | ios::out);
myfile << endl << moiz.name << endl;
myfile << moiz.age << endl;
myfile << moiz.GetGpa();
myfile.close();
}
void deleting()
{
string line, name;
cout << "Please Enter the name of record you want to delete: ";
cin >> name;
ifstream myfile;
ofstream temp;
myfile.open("record.txt");
temp.open("temp.txt");
while (getline(myfile, line))
{
if (line != name)
temp << line << endl;
}
cout << "The record with the name " << name << " has been deleted if it exsisted" << endl;
myfile.close();
temp.close();
remove("record.txt");
rename("temp.txt", "record.txt");
}
void searching()
{
ifstream fileInput;
fileInput.open("record.txt");
string line, search;
cout << "Please enter the term to search: ";
cin >> search;
for (unsigned int curLine = 0; getline(fileInput, line); curLine++)
{
if (line.find(search) != string::npos)
{
cout << "found: " << search << " on line: " << curLine << endl;
}
else
{
cout << "Error! Not found on Line" << curLine << endl;
}
}
}
You can add an else clause to your statement checking the name, and introduce a counter of how many of the following lines should be skipped after name was found:
int skip = 0;
while (getline(myfile, line)) {
if ((line != name) && !(skip > 0)) {
temp << line << endl;
}
else {
if(skip == 0) {
skip = 2; // Skip the next two lines also
}
else {
--skip;
}
}
}