C/C++ :: How To Structure And Write A Class For Text File Streams
Apr 20, 2014
I 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:
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.
I seem to be missing a concept or 2 here ... I am tasked with writing a program that reads text from a file and outputs each line to the screen as well as to another file PRECEDED by a line number ...
In addition, I have to Print the line number at the start of the line and right-adjusted in a field of 3 spaces ...
Follow the line number with a colon then 1 space, then the text of the line.
Another kicker, is I have to grab the data 1 character at a time and write code to ignore leading blanks on each line.
Here is what I have so far:
#include <iostream> #include <conio.h> #include <fstream> #include <string> #include <cstdlib> #include <cctype> using namespace std; int main() { char next; int count = 0;
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.
I have to implemente the to_string method. Whats the fastest way? Stringstreams. But I have to use C++ without any headers, so I need to implement the stringstream class. How can an stringstream hold one float? An double? Hoq cqn I implement an strigstream myself?
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(){
I am trying to use arithmetic on structure members read from separate text files into separate functions. I'm trying to do the math in the main function after calling the other two functions. I'm trying to divide nato_attack by pact_defence.
The warning I'm getting is: both are being used uninitialized in this function.
The goal is to read/write the info in the text files and to use them as any other variable, i.e. add, subtract, etc. in other locations in my code, i.e. functions, modules.
I "borrowed" most of this code from a youtube lesson and modified it for my needs.
Below is the contents of the two text files and my code.
This is for NATO 6 12 4th_mech_div mech div 14 16 7 12 5th_mech_div mech div 10 8 7 12 3rd_mech_div mech div 5 6 6 12 1st_mech_div mech div 4 6 7 12 2nd_mech_div mech div 12 14 7 12 6th_mech_div mech div 8 12 6
This is for Pact 3 10 1st_Guards armor div 12 8 6 10 2nd_Guards armor div 12 9 6 10 3rd_Guards mechanized div 10 9 6
There are 7 candidates and 365 votes in total. I need to do this using an array of structures. I need to read from a text file each of the names of the candidate and the number of votes they get. At the end i need to output the winner of the election.
Each candidate gets +1 vote for their number electionCandidate[0] for each one he gets one vote and so on for the rest. 365 voters in total.
I was able to input the name for each Candidate from the text file. Now the problem is putting each vote to the corresponding candidate. Also any vote that is above 7 is a spoilt vote which i am trying to count in the above code. The code compiles but it crashes.
I am using while(!feof) but it seems that its not working or this is not the correct way.
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.
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;
I 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;
getting 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:
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?
So 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: #include<iostream> #include<conio.h> #include<string.h> #include<ostream> #include<fstream> #include<iomanip> using namespace std; class MathProblem {
[Code] ...
So my program is quite simple, have the user answer the answer to a question, and then compare with the correct answer. I needed to implement an inheritance of MathProblem in my second class aswell.
The program runs as I intend but I wish to have the data forwarded to a text file. After that I must read back to the command prompt the text file contents. It's fairly easy for simple statements but I don't understand how to forward all my data from my classes.
I'm having trouble in getting my program to read from a file and put all the proper data into its proper class variables. I have a class (called Champion) that has string variable for a name and a vector of strings for items. I also have a vector of Champion that holds multiple champions. Here's my code:
I am trying to do some exercises but am struggling at the moment. The first task was to create a class (Planet), then allow the user to edit their entry or view it.
The second one is to create class instances from a text file. The file contains a new planet on each line in the form: 'id x y z' where x/y/z are its coordinates. As the file can have more then one lines, it has to dynamically create an undefined amount of class instances.
To do this I used 'new' and it works ok - it prints each one out to the screen as you go so you can see it working. However... I'm trying to get into good habits here and am encapsulating the class which is where I am getting stuck. I can read from the class but cannot put the values from the file into the class.. ..using the member functions I have created anyway.
My code so far is:
#include <iostream> #include <fstream> #include <string> using namespace std; class Planet { private: int id=0; float x_coord=0.0, y_coord=0.0, z_coord=0.0; public: int GetID(){return id;}
[code]....
If I change the SetID etc to just p->id, p->x_coord etc it works fine. But I'd rather find a way to do it that keeps the encapsulation. Using p->z_coord etc requires that you change the class variables from private to public.
The question I have been given is this:
Define and implement a function, generate planet, that takes a stream argument that has already been connected to a file (i.e. the argument is istream& fin). The function must create a new instance of planet using new and read its details from the next line in the file.Each line of the file is in the format id x y z.The function must return the newly created planet.
Also, how would you go about 'viewing' one specific class instance once they've been created? So say the file had 5 lines, line three was '4 6 2 6'. How would I go about viewing that planet afterwards? I don't think thats required but... I'm just wondering Although I'm also wondering, are we actually creating a new class instance for each line here? Or just destroying the previous one?
So I'm rewriting an old project of mine, and I'm trying to determine if there's truly any better way to map the data taken from a text file "dictionary" into the correct class fields for further processing. For example:
In each of these, I'd need the "value" (MY_FIRST_NAME, MY_LAST_NAME, etc) from the "keys" (FNAME, LNAME, etc) to be mapped to the proper class fields. Say, for example, I had this:
Class DataProcessing { public string Address; public string FirstName; public string LastName; public int TotalCalls; ... }
I would need DataProcessing.Address to be set to the value in the ADDR key/value pair. The same would be true for each other field. The problem is that based on the text file's source (which isn't under my control, and won't be changed anytime soon), the key/value pairs are not always in the same place...so a second file could have the data as such:
TOTCALLS=47 ADDR=123 SOMEWHERE LN, NOWHERESVILLE, TX 01234 LNAME=DARKPOETCC'S LAST NAME FNAME=DARKPOETCC'S FIRST NAME
Any smarter way to do this than looping through each line that was read in from the file, and determining where it belongs, such as (pseudo code follows):
IF FieldName == "TOTCALLS" THEN //Assign to TotalCalls field ELSEIF FieldName == "ADDR" THEN //Assign to Address field ELSEIF FieldName == (You get the picture...) //Do thing N_Field
Write a class definition for a Fraction class. Its member fields are num and den, both of type int. The constructor builds the default fraction 1/1. It has the following operations:
void plusEquals(Fraction second); //Adds the second fraction to this fraction like the operator += void minusEquals (Fraction second); //Subtracts the second fraction from this fraction void timesEquals (Fraction second); //Divides this fraction by the second fraction void dividesEquals (Fraction second); // Divides this fraction by the second fraction void reduce(); // Reduces this fraction to lowest terms double todecimal(); //returns the decimal value of this fraction void scan(istream&); //scans a fraction written with a slash as in ¾ void print(ostream&); //prints a fraction using a slash Fraction(); //constructs a default fraction with denominator 1, numerator 0 Fraction(int n, int d); //constructs a fraction given value for num and den
2. Write a menu-driven driver program designed to allow thorough testing of your Fraction class.
Been given an assignment to create a predictive text program. What data structure I should use for this and the steps I should take when I make the program?
The goal is to write a c++ program to read the employee.dat(which is this text file below) file created and produce a duplicate copy of the file named employee.bak.
Anthony A 10031 11.82 12182010 Burrows W 10067 12.14 692011 Fain B 10083 10.79 5182011 Janney P 10095 12.57 9282008 Smith G 10105 9.50 12202006
and then the second question is to modify this program to accept the names of the original and duplicate files as user input.
#include <iostream> #include <fstream> #include <cstdlib> // for exit #include <string> using namespace std; int main() { ifstream inFile; ofstream outFile;
