I'm supposed to add two new functions to an existing class that I've written early on: readData(ifstream&)and writeData(ofstream&).
The parameters of the program are:
-Create three employee objects as shown,
-Create an ofstream object and open a file. Choose any name for the file that you want. Do not ask the user for the file name. Pass just the file name as the parameter (no path) so that your program assumes the file to be in the same folder as your executable file.
-Send messages to each of the three Employee objects to write themselves out to the file.
-Close the file.
...
If I get writeData(ofstream&) function bit to work! for brevity I've cut all the functions of the class that arent necessary. Here's what I have so far:
Employee.h
#pragma once
#include<string>
using namespace std;
[Code] ....
So I've tried a bunch of different ways to get my objects into the ofstream object to write them to the file, but I'm supposed to use the two new functions somehow...but I'm way lost.
How to get this thing to work. All i need to do is ask user to input a name and then it brings out the line from the .txt file containing the information.
For example in my case I'm doing a member search function I'm required to ask user to input the name of the customer and then print out all the details (which consumes 1 text line in the .txt file)
Here is the code, This is the write to text file method (100% working)
I need to create a function in my program to open an input file and another function to open an output file and I need to use the files in other functions so Im trying to pass the stream object by reference but then i need a condition that tells the compiler not to reopen the file because then it will delete everything and make me input the file names again. Heres the two functions.
Issue 1: I am using a stringstream object in a block of my program that needs to be visited repeatedly depending on a user's selection from a menu. I want the contents of this stringstream object to be cleared any time control gets to this part of the program. I have tried the clear and flush functions to no avail.
Issue 2: I am reading data from a source text file that would be regularly changed during the course of program run. After the program run is over, I am supposed to save the results(which is basically the source text file AND all updates) in a destination file. This destination file would then serve as the source file when next the program is run. In other words, I want a scenario where my results overwrite the original contents of the source file; implying that my source and destination files are now one, pretty much. How can I do this?
Try to implement overloading << operator. If I done it void then everything work fine (see comment out) if I make it class of ostream& then the operator return to me some memory address.
Code: #ifndef Point_HPP // anti multiply including gates #define Point_HPP #include <sstream> class Point { private:// declaration of private data members double x;// X coordinate double y;// Y coordinate
I wrote a program to write text contents to file stream through fputs, the file stream address was changed in the middle of writing text content to the stream (11% text content have been put into the file stream), that cause the file stream pointer can be evaluated problem and raise exception on stream validation code in fputs library function, my question is what things could go wrong to make file stream pointer changed its address to something else or a NULL pointer if the file stream have not been flushed and closed.
On fairly rare occasions, when attempting to debug one of my MFC applications on VS 2010, a compilation error is encountered, and instead of bringing up the customary Windows or MFC file with a arrow pointing to the problem, a disassembly appears with an arrow pointing to one of the assembler instructions.
Since Windows assembly language is hardly my forte, I do not know how to interpret the error. Furthermore, the Output usually indicates one or more 'first chance exceptions' but little more, and the Stack output usually quite sparse and often refers cryptically to some ntdll.dll!7c92a82c().
I have function which will replace (or create) an file with the contents of another stream. The stream could be anything. The replacement is done safely.
Code: #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <limits.h> #include <unistd.h> int do_replace(const char *file, int stream, int cnt) {
I would like to have 2 functions. (FYI, I haven't even tested these because I don't have a compiler on this PC, so don't know what they'll do. I'm also new to C++, self-teaching.)
My question is, I'm sure that oFile should be type object (of some sort), not int, but I'm not sure how to reference it correctly so that it passes from FileOpen to main to FileClose.
Code: #include <iostream> //I/O using namespace std; #include <fstream> //files using namespace ios; int FileOpen(string fileName) { ifstream oFile (fileName); //attempt to open file
It works, when the object is passed, except for two cases (one where the minus sign shifts) and whenever there is a zero or a negative integer in the denominator.
Also, I'm passing the function like validInput(c);
i need to pass myboard.board (board is in the class Cboard and it is an array of int) to a function in a class called piece however this is troubling . i need to pass it as pointer os that i could change its value here under is my code.
Is it correct for me to make a clone of testobj in function AddTest below, before i add it to my map? What i want is an user pass testobj to me though AddTest, and after i add it into my map, i do not want to have anything to do with the original testobj anymore. I.e, they are two copies, one belong to Device, one belong to the caller, both has no link to each other.
Also regarding the GetTest method, i prefer to return a raw pointer, as i do not want to force the caller to use smart pointer. And i also do not want the caller to be able to do anything that may change testobj in the map. So i am not sure to return as const reference or make a clone of testobj on the map and return it to the user (but caller need to delete the testobj when it is not used).
my program crash when it try to assign the return value of the function to the local value. extract function does return correct value, but it just crash when done executing.
I have a school project in which need to create a function that takes a File Object as a Reference Parameter. Supposedly, it should allow me to read the first piece of data from others separated by a space from a file. The later be able to continue reading from the next piece of data.
I know how to set things up to read from the data file, such as using
Write a function named replaceSubstring. The function should accept three C-string or string object arguments.
Let's call them string1, string2, and string3. It should search string1 for all occurrences of string2. When it finds an occurrence of string2, it should replace it with string3.
For example, suppose the three arguments have the following values:
string1: "the dog jumped over the fence" string2: "the" string3: "that"
With these three arguments, the function would return a string object with the value "that dog jumped over that fence." Demonstrate the function in a complete program.
I'm trying to write a function for receiving messages, so my classes can communicate with each other. The only issue I get is a compile error asking me to define the base parameter as one of the derived instances. I tried using a void* to fill the need, but then I lose the initial type, which I need to check for. How might I go about writing a generic object for this?
Here's my code:
template<class Object> class State { public:
[Code].....
Should I just have all of the objects inherit in the order of Object >> GenericObject >> DerivedObject?
I have found that when I dump a C++ object from memory to a file - it seems that there is a misplacement of the last Virtual-Function-Table pointer - in that appears at the beginning. The result is that the gdump information based on this object dump (using green hills) is incorrect. I copied the contents of the gdump information below. The executable is compiled in linux.
Basically MEIO::CameraStatus contains an item that relates to its parent class (line 188). Then it has 18 items that are all Diagnostics::EventsCounter items. Now for each Diagnostics::EventsCounter item there is a Virtual-Function-Table Info Pointer as its last item. All is fine and good except that the last item of MEIO::CameraStatus which is _selfReset is missing its last item of 4 bytes (which is the Virtual-Function-Table Info Pointer ). On the other hand - right before the first Diagnostics::EventsCounter item ("_vidErrors") - there is an extra 4 bytes which happens to be the Virtual-Function-Table Info Pointer. As I said the gdump information file does not see this.
Why the object memory "moves" the last Virtual-Function-Table Info Pointer to the beginning (right before _vidErrors) and is there a way to "fix" this?
/////////////////////////////////////////////////////////////////////////// "MEIO::CameraStatus" val:0x000002f0 ind208,-1) Struct-Begin Info 188: "" offset 0, Parent-Class Private Info C++ Struct ref = 114 189: "_vidErrors" offset 160, Member Info C++ Struct ref = 128 190: "_vdiErrors" offset 480, Member Info C++ Struct ref = 128
I know if i will not use the pointer base class function "virtual double grossPay" will be called for both base class object and derived class object and when i will use pointer with reference to the object because base class function is virtual it will look for same function in derived class and if available it will execute it.
will copy constructor does object initialization using another already created object? I understand that it can be applied for object initialization and not for assignment.Is it correct?
