I wonder why this program does not do any changes to the text file that I am trying to modify. Scenario: My program uses the Fstream header file, I declared infile as IFSTREAM and outfile as OFSTREAM. I simply want to transfer data from infile to outfile. The data is as follows; Adam Larson 89 90 This data is saved in a text file manually created with Notepad. Furthermore, I also want to add the average of 89 and 90 into the outfile target file however, it doesn't do it. it does nothing at all. I also observed that there …

Member Avatar
Member Avatar
+0 forum 4

Hello everybody! I'm trying to count the number of occurrences of each word in a text file. Problem situation requires to realize menu using "switch" statement (If file exist or not). There are following errors in my program ("case b" and "default" is not working): **[C++ Error] 03_int.cpp(61): E2126 Case bypasses initialization of a local variable [C++ Error] 03_int.cpp(72): E2238 Multiple declaration for 'w' [C++ Error] 03_int.cpp(50): E2344 Earlier declaration of 'w' [C++ Error] 03_int.cpp(83): E2126 Case bypasses initialization of a local variable** #include <fstream.h> #include <iostream.h> #include <map.h> #include <string> #include <cstdlib> #include <iomanip> #include <conio.h> typedef std::map<std::string, int> …

Member Avatar
Member Avatar
+0 forum 8

I'm trying to store the contents of a file containing names of herbs and spices (items) in a 2D array called PantryContents. Then I'm trying to add an item to that array. It seems like only one item is being stored at a time, but the output is correct but when I check the content of PantryContents, only one item shows up (like it's not 2D). This will be split into functions eventually.. (that's why the format is a little funky), I just needed to make it work all together first. Any ideas? This is what's in the file "Pantry.txt": …

Member Avatar
Member Avatar
+0 forum 2

Dear Kind DaniWebbers, I am trying to overload the fstream operators (ofstream/ifstream), so that I can save a class to a 'Binary' file and also display it with cout. But the ways in which each need to be implemented is different. Please can you show me how to define different operators for each. Here is my test class: class CBase { public: //CBase(void) {}; CBase(int i = 0, float f = float(0.0), double d = double(0.0), char c = 'A') : iMyInt(i), fMyFloat(f), dMyDouble(d), cMyChar(c) {} ~CBase(void) {} int iMyInt; float fMyFloat; double dMyDouble; char cMyChar; friend std::ostream& operator<<(std::ostream& os, …

Member Avatar
Member Avatar
+0 forum 4

I'm having a simple i/o with file problem. I have the name coming from a string but it just wont open at all. Incoming code: string notename[] = {"NULL","empty"}; ifstream readnote; readnote.open(notename[x].c_str(),ios::in|ios::out); if(!readnote) { cout << "Read Error"; } its prolly something small but i keep getting the error, can u see it?

Member Avatar
Member Avatar
+0 forum 2

For my c++ class i have to write a code that will read integers in to a 2D array from a file and then, using functions/methods, determine if the array is a magic square. My problem is that when i build or compile i get "error C2664: 'DataIn' : cannot convert parameter 1 from 'std::ifstream' to 'std::fstream &'" Here is the code: #include <iostream> #include <fstream> using namespace std; void PrintMatrix( int x[][20], int size) { for(int i = 0; i < size; ++i) { for(int j = 0; j < size; ++j) { cout << x[i][j] << "\t"; } …

Member Avatar
Member Avatar
+0 forum 4

Please, I know this is a simple question. I'm copying this code out of my text book, almost ver-mother#&$(ing-batm And it mother#&$(ing refueses, REFUSES to open the mother#&$(ing file and write to the mother#&$(ing array. WTF - Sorry for the language, but this is so stupid and silly and I have NO mother#&$(ing clue why this isn't working. I've spent more time than I want to admit publicly on this problem PLEASE HELP! What's happening is ifstream is doing God-knows-what, and then it creates an array and that array if filled with what ever crap was in that memory location. …

Member Avatar
Member Avatar
+0 forum 3

So i just started my project on a cpu sim , but right of the bat i ran into a problem #include <cstdlib> #include <fstream> #include <iostream> using namespace std; /* * */ int main(int argc, char** argv) { return 0; } void cpu() { } void memory() { int memArray[1000]; ifstream infile; infile.open("program.txt"); } my ifstream is having trouble, i think it has to do with the headers but i dont know how to fix this , am kind of bearly picking up c++ again. So any help is appriciated, ok between using netbeans ide, and i also already …

Member Avatar
Member Avatar
+0 forum 2

It seems I don't understand completely reading from and into files, line by line. Here is my code that is supposed to read lines of two file, into string variables, I assume, and then write them into third file: *line of first file line of second file .... so on if one of files ends, the rest of the other is added to the end* Where is my mistakes? it compiled, but did not write anything into third file #include <iostream> #include <string> #include <fstream> using namespace std; int main () { string name1, name2, line1, line2, name3; cin>>name1; cin>>name2; …

Member Avatar
Member Avatar
+0 forum 3

Can some one briefly tell me about that how to do fileprocessing in c++

Member Avatar
Member Avatar
+0 forum 2

Hi everyone, First post here so feel free to school me if my etiquette needs it. I'm reading a very long string of data (genome stuff AT TT GT AA AG AA ... etc) and comparing it using hamming distance with a similar string. (Naively checking for similarity entry by entry). I have quite a few questions to put to you but lets begin with one that will probably demonstrate my level of C++. My code reads as follows: int main () { ifstream indata; string str[2][899701]; int j,count; indata.open("file"); if(!indata) { cerr << "Error: file could not be opened" …

Member Avatar
Member Avatar
+0 forum 5

Consider the following. I have a text file with 5 rows of 5 characters each. I want to read in a line and then compare it to all the other lines. I create 2 ifstream objects pointing to the same file, first and second. first reads in the first line. I would then like second to take over from first, effectively starting at that position in the file and compare the remaining lines until the end of the file. first then is in the right position to read in the second line. second would again take over from first and …

Member Avatar
Member Avatar
+0 forum 1

So here is my problem. My program's goal is to to find the shortest path for a maze in a text file. User inputs a string and then the string goes through a function that reads the file into a 2d array. My problem is that I'm seperating the sources in to a header file and a seperate source file. And because of it I can't get it to work. Please help! My code with the functions is this: ...ps my error occurs in the readMaze funct. #include "maze.h" #include <iostream> #include <fstream> #include <string> using namespace std; void Maze:: …

Member Avatar
Member Avatar
+0 forum 1

I'm missing something obvious here I think I'm trying to check for the existence of a file, and I hear this is possible with ifstream's .good property. Not even managing to get that far. Forgive me on this, I'm new to C++ Created a new VS console application. I then added the relevant includes: #include <iostream> #include <fstream> #include "stdafx.h" After that, I tried an example I found on the web: std::ifstream my_file("file.txt"); Adding this to my main. Rather than using namespace std; I decided to just reference it fully here as this is the only time I will use …

Member Avatar
Member Avatar
+0 forum 3

a friend asked me to help him with his lab. the lab involves opening a file and adding the numbers in the file together displaying how many even and how many odd numbers there are. I have the file "textinput.txt" in the directory with the .cpp file but when i build i still get the error message. I don't get why. I'm using XCode if that helps. Did i forget to include a correct library or is there something about how XCode reads the ifstream.open that i do not completely understand? [CODE] #include <iostream> #include <fstream> #include <cmath> #include <cstdlib> …

Member Avatar
Member Avatar
+0 forum 4

//////////////////////////////////////////////////////////////////////////////////////// // In this little project I am trying to learn to get and manipulate data from // a file input using fstream strings I also wanted to use the formating available // with the printf and related string handling methods. I have a question in regards // to the two usages that I have shown in order to get char * from std::string. // // Is there a differance between the two things I have done? // Is one safer than the other because of allocatin for size? // Does it matter? // // Does anyone have any comments …

Member Avatar
Member Avatar
+0 forum 2

Guys, I've been stuck on this for a while now. This is actually one of my assignments, and I'm really lost. This is the assignment: ------------------------------------------------------------------------------------------- You manage a .txt file containing the customer ID number and account balance of the members of a bank. Last week, a computing error caused each customer's account balance to get reversed. For example, if someone had an account balance of 132.64, this was reversed to become: 462.31. Write a program which will input the file and output a file containing the corrected account balances next to each customer ID number (a 9 digit …

Member Avatar
Member Avatar
+0 forum 32

Hi-- I am new to C++ and am having trouble with this program: The objective is to take input from a file and write it to output, using the '|' character as the delimiter, but displaying it using a comma (ex, if line 1 is "1000|6 1 6 5 3 2 | Paramus | NJ", the output would be "1000, 6 1 6 5 3 2, paramus, NJ". (the six random numbers are supposed to be test question responses, but that's largely irrelevant.) What i have so far is as follows: [CODE]ifstream reader; reader.open("SurveyResponse.txt"); char line[15]; int i=0; while( !reader.eof() …

Member Avatar
Member Avatar
+0 forum 1

So, I've been assigned to write a program that reads the wind-tunnel test data, that of which is called the "tunnel.dat" in my program, and then allows the user to enter a flight-path angle. If the angle entered is within the bounds of the data set, the program would need to do linear interpolation to compute the corresponding coefficient of lift, given by f_b = f_a + ((b-a)/(a-c)) * (f_c - f_a) The problem I'm having is that the program has successfully compiled, however the result isn't turning out as it should be. It's returning "The coefficient of lift is …

Member Avatar
Member Avatar
+0 forum 7

Ok so I want to have the user imput a name of a file to decode it. How would I do that? EX: cin>>fill ifstream in (fill)

Member Avatar
Member Avatar
+0 forum 7

In writing a logfile program, I need a function to output the log entries between two dates. I use [ICODE]seekg()[/ICODE] and [ICODE]tellg()[/ICODE] to save the position of the first entry to output and last entry and then go back later to output the data in between. However, [ICODE]seekg()[/ICODE] when told to seek back to the beginning position goes to position -1 (can be seen when ran through a debugger), and no output is created. seekg() works fine when seeking in other parts of the program. [CODE]#include <fstream> #include <time.h> #include <string> #include <sys/stat.h> #include <iostream> #include <stdbool.h> #include <cstdlib> struct …

Member Avatar
Member Avatar
+0 forum 1

I need to read data from a file into an array of structs. The info is arranged in the file like so... Spear of Extreme Whaling January 1851 Captain Ahab Each member of the array has a name, month, year, and first and last name of creator. This is the beginning of my code: [CODE]#include<iostream> #include<fstream> #include<string> #include<iomanip> using namespace std; struct artifact { string name; string month; int year; string fname; string lname; }; int main() { artifact allInfo[31]; char menu; char yn; int j=0; string name; string filename; string yearTemp; ifstream inFile; ofstream outFile; cout<<"Enter a file name: …

Member Avatar
Member Avatar
+0 forum 1

Hi all, I'm sure it's an error by me, but I'm having a problem with ifstream inside a loop. The reason for the loop is read in a piece of text from multiple files, and cases within the switch statement change the filename, path is previously declared. The first iteration of the for loop always works and the value "chamberarrayval" is output, but the subsequent values from the subsequent files never materialise. The switch statement is OK as I've tried the cases in isolation without the loop. Do I need to define ifstream everytime or something else? Any help much …

Member Avatar
Member Avatar
+0 forum 4

Hello guys! I'm having a rather pesky problem working with fstream. I could write, for example: [CODE]fstream file("text.txt");[/CODE] then file should be open in read/write mode. But then if I do the following: [CODE]file << "Some text"; file >> string_var;[/CODE] or in the opposite order, it will only perform the first operation. I've even tried with seekp() but it still happens, even if I do: [CODE]file.open("text.txt",ios::out); file << "A word!"; file.close(); file.open("text.txt",ios::in); file >> aString;[/CODE] The only way i've found to fix this is creating two separate fstreams but it seems not right... Also, if I try to open different …

Member Avatar
Member Avatar
+0 forum 1

I'm having trouble figuring out how to use exceptions to check if a file stream was created successfully. I know I can use if statements, but how do I do this using try/catch statements? It compiles successfully but it gives me an error when I supply a non-existent filename as an argument. If I supply a file that does exist, it runs fine. The message I get when I give it a bogus filename is: [code] terminate called after throwing an instance of 'char*' Abort trap [/code] [code=cpp] #include <iostream> #include <fstream> #include <exception> int main(int argc, char *argv[]) { …

Member Avatar
Member Avatar
+0 forum 2

[CODE=c] int main(int argc, char *argv[]) { ifstream inHandle; Assembler obj; if(argc!=2) { cout<<"InvalidInput ERROR"; } else { inHandle.open("test.asm"); if(inHandle==0) cout<<"FileNotFound ERROR"; else obj.pass1(inHandle); } inHandle.close(); return 0; } [/CODE] this is my code for the main() function, i have tried entering the filename in every possible format but the control always jumps to.. [CODE=c] if(inHandle==0) cout<<"FileNotFound ERROR"; [/CODE] ..Can anyone please suggest me what the problem could be?!? NOTE: i am using TurboC++ v3.0

Member Avatar
Member Avatar
+0 forum 8

Hi, I'm having trouble displaying the numbers in the file on the screen. The numbers are in the .data files but i cant get them to display. [CODE]//****************************************************************************** // Exercise: Homework 07 Arrays and pointers // This program reads two sets of integers from the text files A.data and B.data. // The program finds the intersection of the two sets (which is the // set of numbers contained in both sets). The intersecting // values are displayed and saved in C.data with the same file format // tha A.data and B.data, is that to say, one interger in each line …

Member Avatar
Member Avatar
+0 forum 9

Hello I am trying to read from a file. I'm followed a tutorial and had it working perfectly before, and it still does now.. But the problem is that one variable that I'm reading from the file is causing my program to crash. All the other vars I'm reading, are fine. And I know its the one variable cause I pinpointed it out. Commented it out, the program runs fine. With it, crash. The crash is a simple "The program has stop responding..." then closes. The other problem is that this value is important to read, as without it there's …

Member Avatar
Member Avatar
+0 forum 6

Hi, Please help... I am trying to read in a file in C++ and when I use getline I am not able to read in the last line when the last line in the input file does not have a newline (\n) at the end. How do I do this? I am reading a file with getline as such: [CODE]if (file.is_open()) { //get first line getline (file,line); //do something - write output }[/CODE]

Member Avatar
Member Avatar
+0 forum 10

For some reason im getting stuck in a loop after i enter in my "numberinput" i have a mimic case that does the same thing but with characters instead of numbers, and it seems to work perfectly all this is doing is checking to see how many times the user defined number is inside a premade file. [CODE] case '2': infile.open("numbers.dat"); if (infile.fail()) { cout << "Error opening input file -- program terminated!\n"; return 0; } //number input cout << "\nEnter number to count: "; cin >> numberinput; cout << endl; //priming read infile >> number; //looping count while (!infile.eof()) …

Member Avatar
Member Avatar
+0 forum 14

The End.