I need to a simple example for writing class' objects to a text file using fstream , I tried to search the forums and I found binary examples but not for to a text file.
View 8 RepliesSo I have a small program which is supposed to write and read multiple objects from a file, but for some reason it doesn't write the information when I use "fstream" to create the object from the fstream class, but it does when I use "ofstream". Also, it doesn't read the information from the file no matter if I use "fstream" or "ifstream". I watched a video where this exact code worked just fine, but it just won't work when I run it. I'm using Dev C++ 4.9.9.2, I don't know if that has anything to do with it, I also tried it with Code::Blocks, didn't work either.
Here's the code.
#include <iostream>
#include <fstream>
using namespace std;
class Person
[Code].....
if i have 2 variables for which values are given by the user,then,does the information get stored into the file in the name of the variable,or just like packs of information.....if the former is true,how to extract the information of a particular variable alone from the whole file?
View 4 Replies View RelatedI need to make a program which reads multiple lines from a text file and stores that information in a vector of structs(the vector class template also needs to be custom made).
One of my requirements is to have a class dedicated for I/O for the text file. At the moment I can't seem to get a way to input the data from a file into a vector from an InputOutput class. This is my code:
InputOutput.h
#include <ostream>
#include <fstream>
#include "Share.h"
#include <string>
#include "Vector.h"
class InputOutput {
[Code] ....
This is the menu selection function in the menu.cpp where i figured i would call the Input file and store it from case 1. I think I'm doing it wrong though. Is there a better way of doing this because at the moment i am getting some errors such as error LNK2019.
void Menu::UserMenuSelection() {
Vector<Share> shares;
std::ifstream infile;
switch (menuOption) {
[Code] ....
I'm trying to make a simple phonebook app that can show contacts, add, and delete. I'm pretty new to C++ and fstream functions, deleting a line in my bool erase() function?
#include <iostream>
#include <conio.h>
#include <string>
[Code].....
fstream ifs;
ifs.open ("data.str", ios::binary | ios:ut);
char *data1 = "data1";
char *data2 = "data2";
ifs.write(data1, strlen(data1));
ifs.write(data2, strlen(data2));
when i this,data2 is not going under data1, i thought each write starts on a new line?
Basically for homework, we gotta make an array of payroll objects, using the general format I've made below...
I'm having trouble. The .dat file we are given to test looks like this:
40.0 10.00
38.5 9.50
16.0 7.50
42.5 8.25
22.5 9.50
40.0 8.00
38.0 8.00
40.0 9.00
44.0 11.75
When I execute the program, it shows the first column of objects, but will always replace the 2nd column values with a 0.
It's definitely NOT reading that column, and using the constructor to set it to zero. I don't know why it's not reading that column though...
(TL;DR.... Currently it reads "Employee #1: 40, 0" rather than "Employee #1: 40, 10.00"... etc)
Here's my code.... (not 100% done yet just testing datafile output atm)
#include <iostream>
#include <fstream>
using namespace std;
class Payroll {
private:
double payRate; // holds an employee hourly pay rate
[code]....
I want it to read the other column without giving me zero />
I am working with a new text adventure. The way i want to construct it is by having a class for all living things. in the class you have basic things as: health, gold, vector for inventory holding "struct item". etc...
There is also a class called world, wich navigates through the world.
World class contains of: player location, and a map containing info about the room etc...
Here comes the problem. I want there to be characters to be placed out in different maps, so basically i want the world class to hold objects from Character.
How to do it. In world class i made a map...
std::map<int,"content">
content is a struct i made above in world class:
struct content{
std::string name; // location name
std::string info; // info about location
std::vector<Character>characters;
std::vector<item>items;
};
To sum it up, i have a std::map<int,content>map the int stands for location id. Content holds more info about the room and what's in it
btw the classes are in different files and that means i have to include "Character.h" in the world file so i can set up the vector of characters.
The Objective Of This Program Is To Create A File To Write Text And Read Back The File Content. To Do That I Have Made Two Function writeFile() To Write And readFile() To Read.The readFile() function works just fine but writeFile() doesn't.
How writeFile() function Works? when writeFile() function Execute It Takes Characters User Type And When Hit Enter(ASC|| 10) It Ask "More?(Y/N)" That Means What User Want? Want To Go Next Line Or End Input?
If "Y" Than Inputs Are Taken From Next Line Else Input Ends.
But The Problem Is When Program Encounters ch==10 It Shows "More?(Y/N)" And Takes Input In cmd variable.If cmd=='Y' I Mean More From Next Line Than It Should Execute Scanf Again To Take ch I Mean User Input.But Its Not!!! Its Always Showing "More?(Y/N)" Again And Again Like A Loop.
Code:
#include <stdio.h>
void writeFile(void);
void readFile(void);
int main(){
[Code].....
I have a .txt file which I want to read from and then write a new text file, this time with sorted lines. It is easy to sort one value, but what about sorting entire lines based on one value?
I want to sort the lines based on the FIRST value.
Example text file contents:
values;data
5.01 100
2.9 342
2.69 43534
10.1 43
6.8 45324
Output: Text file containing
2.69 43534
2.9 342
5.01 100
6.8 45324
10.1 43
It's easy to do this if there was only 1 number on each line, but I do I sort all the lines based on the first number in each line?
I have looked through te tutorials here, and even google it, as well as tried to follow the power points from my class..but I still can't seem to figure out how to make this code work correctly.. Basically I have to create a file called grade and write to it a student name and their grade score, and then read from the file all students names and there grade and display this on the screen as well as calculate the grade average for all of the students and display it.
Well I am able to write to the text file, but I can't seem to get the rest to work. I can't figure out how to read from the text file..Here is my code below.
write a sample code that does something similar write to text file string and numbers and then reads from it.
#include <iostream>
#include <fstream>
using namespace std;
[Code].....
I want to design a class that will open a text file and manipulate the data in it. And I have to use all these functions from fstream like ifstream, ofstream, seekg etc. The problem is that I can't get the first part to work (getting my constructor to open the file using ifstream). I've posted my test.h file below.
#ifndef TEST_H_INCLUDED
#define TEST_H_INCLUDED
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
using std::ifstream;
class Test {
[Code] ....
I've a text file : Random.txt which comprises of
Jade
12MS234
Male
18
Rocky
12MS324
Male
18
Marx
12MS632
Male
18
Now in my program i've a class
class stud
{
char name[10];
char reg[10];
char gender[10];
int age;
};
Now I've to write a code in c++, where i've to read the given data and store this into 3 objects of stud class(array of objects) ...then further i've to manipulate the above stored data. I think i'm getting error while storing...variables are showing random characters... give me the code.for this program..in C++
Simultaneous Reading and write from and to a text file using Multithreading in c/C++
View 1 Replies View RelatedI need to write a program that reads four float numbers from the input.txt file, then it prints out the greatest of the four numbers into the output.txt file. I did everything, but the numbers don't print out.
#include <iostream>
#include <fstream>
using namespace std;
int main() {
ifstream inFile;
ofstream outFile;
float number1, number2, number3, number4;
[Code]...
How to write in DOS encoding using class FILE ?
View 5 Replies View Relatedgetting hex from a text file and writing it to a different file. I made a program to dump hex from files into a text file and now I need it to save the hex to the original file. Here is my code to save the hex:
int main(int argc, char * argv[]) {
ofstream myFile;
ifstream file(argv[1], ios::in);
[Code].....
It never outputs the correct contents of the file that has been dumped. I've checked with other hex editors and the hex dumper is working correctly.
I'm using
CString text;
CString file_name;
text = "My text.";
file_name = "MyFile.txt";
FILE *fp;
fp = fopen(file_name, "w+");
fprintf(fp, text + "
");
fclose(fp);
There will be MyFile.txt in Windows codepage.
How to write to txt file with DOS codepage?
I am trying to write a program for class that reads from an input file the month, year & total collected. I am using notepad for the input file.
This is what the notepad file looks like
-----------------------------------
March 2013 63924.62
Why does it give me random numbers in the output rather than what the notepad has?
Also, the outfile is completely blank.
#include <iostream>
#include <iomanip>
#include <fstream>
[Code].....
For some unknown reason when i try the following code it doesn't create a file. (the program will simply get two inputs from the user and then use http to obtain the html/php text and then output it to a file)
code:
#include <SFML/Network.hpp>
#include <iostream>
using std::cout;
[Code].....
So, I am making a name-database-type-thing and I want the user to be able to enter there own file. Like, here:
string fileName;
string name;
cout<<"What is your file name?"<<endl;
getline(cin, fileName);
ifstream nameFile(fileName);
getline(cin, name);
nameFile<<"Name: "<<endl;
Well, that last part is in a loop, so you can enter an unlimited number of names to the .txt file.
So, it won't let me use the string in ifstream. How can I fix this? This maybe unclear, so if it is just say so and I will edit it.
I have a file of data where each line consists of 4 parameters (degree, alpha, beta and x) and a value corresponding to these, organized in increasing order of the parameters. Here's the test file I'm using:
0 1 1 0.5 3.5
1 1 1 -0.5 -0.5
1 2 0 0.2 4.5
1 3 0 0.2 -4.5
2 0 0 1.5 2.1
2 1 0 0 5.6
My code is supposed to look for a certain set of parameters (currently set to 1 2 1 1.5, which is not contained in the file) and its value. If it's there (i.e. the file contains the value for the right parameters) the program is done. If not it should calculate the value using a function JacobiPoly() and insert the wanted parameters and corresponding value in the appropriate place in the file.
I have a code in which I think everything works except the writing to file. I use an fstream so I can both read and write and open it with ios::out||ios::in. I'm also aware I need something similar to fseek in between input and output but according to [URL] .... reading and writing to the same file using the same fstream, seekp() should suffice. I'm using seekp(), but the output (in the form inout << (...)) doesn't work.
Here's the code:
fstream inout;
inout.open("inouttest.dat", ios::out | ios::in);
int degree=1, readDeg;
double alpha=2, beta=1, x=1.5, value, readAlpha, readBeta, readX, readVal;
bool foundVal=false;
streampos beforeRead=(streampos)0;
[Code] ....
I want to edit the contents of a file using fstream, but none of the modes in the fstream constructor work for me.
If I use ios::trunc, then the whole file is deleted - but I want to retain the contents and edit it. If I use ios::app, then I can only add data to the end of the file - but I want to edit the data in the middle of the file. If I use ios::ate, then the whole file is deleted again, similar to ios::trunc.
How can I create an fstream object without deleting the contents of the file, whilst still being able to move the pointer arbitrarily around in the file with seekp() (and not just placing it at the end as with ios::app)?
I did some of the projects using STL container and it is pretty much efficient to retrieve the data's information quickly (i.e. sets, sets & maps). I read many C++ OOP book and none of them make me clear about the Link Between (STL) Container and (Fstream) File I/O. Can they link together ?
I am going to design a small Library Book Management Project. I am planning to develop it using the STL Algorithms & containers. Objective of this project is to keeping the records of books issued and deposited by students in a particular date. User will be given a facility to retrieve student's information, book information and he/she can modify/update specific book's, student's information by changing issue date, deposited date, Book's publication etc.
My intention is to create a File I/O where user can input & update/modify daily transaction inside the file called (xx.dat) file in project directory. Is it possible to create 'set' container inside the file (xx.dat) ? Or, It's impossible ? Or, do i have to do this in other way?
How to forbid file replacing in fstream library for C++?
#include <iostream>
#include <fstream>
using namespace std;
int main() {
ofstream myfile;
[Code] ....
other posts talk about the fopen function and don't really give any solutions to this the var that has the file path is a char* and has been converted from a system::string^ it is completely valid when I paste it in windows bar.
Code:
private: System::Void button3_Click(System::Object^ sender, System::EventArgs^ e) {
if(textBox1->Text[0] == (char)'' || textBox2->Text[0] == (char)''){
MessageBox::Show("Please select a valid m3u and path", "Problem",
MessageBoxButtons::OK, MessageBoxIcon::Exclamation);
[Code]....
it crashes right at the pile.open() function call when I put breakpoints in it says , debug assertion failed and shows me the fclose.c file location and Expression: (stream != NULL)