I am trying to separate out particular sets of routines into a separate implentation and header file which can be compiled independently to the main program such that the program source consists of a file called customers.h, customers.cpp, and exercise_1_5.cpp
Each of the files should contain the following:
customers.h should contain the definition of the customer structure and the declaration of print_customers.
customers.cpp should contain the implementation (or definition) for print_customers.
exercise_1_5.cpp should contain an include of customers.h and the main program.
This is my original code from a single .cpp file
#include<iostream> #include<string> using namespace std;
[Code].....
The error messages I am getting from the compiler on the customers.cpp file:
C:UsersBenDocumentsCS264lab3customers.cpp:5:22: error: variable or field 'print_customers' declared void C:UsersBenDocumentsCS264lab3customers.cpp:5:22: error: 'customer' was not declared in this scope C:UsersBenDocumentsCS264lab3customers.cpp:5:32: error: 'head' was not declared in this scope
I am a beginner with C++, taking a class right now. The lab this week is to create a user defined class and have it accesses in a separate .h header file from the main.
I think I'm finding my way through it, but I'm getting a complie error that makes no sense to me:
i have seen many c++ programs, where the private members from a header file are accessed in the source file. why is happening? As to my knowledge a private member cannot be accessed until it is friend function or member.
I have a header file that declares some fields as private, I then have a class that I need to compare two of the objects' information for equality but neither of them are the calling objects. I cannot alter the header file. How would I go about comparing private data fields? I will enter a brief bit of code for clarity.
Code: // Header File // stuff.h
class stuff { private: int* arr[20]; int size; }; bool equal (const stuff& a, const stuff& b);
I have a header file in which we include vector at the top. But we want to remove that include. On doing so I get compilation errors as the header file uses std::vector<> at several instances in header file so I have to forward declare the vector to solve this issue.how i can do it.
I'm working on a grocery store inventory project. One part is to have a shopping cart, where customers can put in up to 20 items. Because there can be up to 20 shopping carts at one time, I want to use a vector inside the cart object to represent all the individual food items.
Here's my code,
Header:
#ifndef CART_H #define CART_H #include <vector> class Cart { public: Cart(); Cart(std::vector< int >, std::vector< int >)
I am trying to pass a 2D array called f (coming from a text file with 9 columns of numbers and 297,680 rows) that was created using the vector container in my main() to the function myfunc. I'm just trying to figure out how to pass the address of f in main() to myfunc(), so that myfunc() has arguments consisting of a pointer g (that accepts the address of f as an input) and an int.
This is the error from the compiler: test_2d.cc: In function ‘int main()’: test_2d.cc:47:25: error: cannot convert ‘std::vector<std::vector<double> >*’ to ‘double (*)[297680][9]’ for argument ‘1’ to ‘int myfunc(double (*)[297680][9], int)’ return myfunc(&f,count); ^ Here is my code:
#include <iostream> #include <fstream> #include <iomanip> //allow setprecision to get all the decimal points #include <vector> #include <string>
I have the following map: myMap<string,vector<int>>. I now want to look through my map to see if a key exists and if it does, retrieve one of the int values from within that vector. What would be the best way to do this? Right now I have the following:
What would be the best way to look for a key and get one of the int values from its vector value? Right now I'm doing something like this:
[code] map<string,vector<unsigned int>>::iterator it; it = wordMap.find(someWord); if(it == wordMap.end){ cout << "No matching entry"; } else{ // this is where I'd want to access the value (the vector) of the map }
I have a vector that I would like to access and work with from multiple threads. I have created an example below to illustrate the functionality that I would like to accomplish.
The goals are to be (1) high speed, (2) thread safe, and (3) *if possible* continue to use vectors as my larger project uses vectors all over the place and as such I would like to maintain that.
However, if I need to switch from vectors to something else then I am open to that as well.
The following example below compiles but crashes rather quickly because it is not thread safe.
How I can fix the example below which I can then apply to my larger project?
I have a vector (structures) in a struct (instances). I make a declaration of this struct called instance. The vector is a 3-layer vector of pointers, like so:
vector < vector < vector<scene::IAnimatedMeshSceneNode*> > > structures; (The type is from Irrlicht 3D). I have 3 nested "for" loops which looks similar to the following:
for (int a = 0; a < instance.structures.size(); a++) { /*note:vector size previously set*/ for (int b = 0; b < instance.structures[a].size(); b++){ for (int c = 0; c < instance.structures[a][b].size(); c++) {
if (1) { //checking value of variable not included in snippet
These are currently referencing the pointers, it seems. The program compiles but crashes at this point. I need them to reference the values of the pointers. Problem is, I don't know where to put the dereference operator (*). Where should it go?
I'm using Visual C++ 6.0 and I'm trying to use fstream to open and read a file that is created only during runtime. This file is written by another function running on another thread, and my program will keep trying to "open" the file until it can be opened, i.e. after it's created, then read 3 numbers from it and execute the rest of its code.
The file test.txt has the content
Code: 1 3 4
My program that polls and opens the file is as follows:
Code: ifstream fin; std::string tfile, snum1, snum2, snum3; long int num2, num3; tfile.assign(argv[1]); printf("Begin prog %s ", tfile.c_str());
[code]....
I executed the program by
Code: test_prog.exe "C: est.txt"
and waited about 3 seconds before putting the test.txt file into C:
My output was
Code: Begin prog C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt fin is open snum1 = num2 = 0 num3 = 0 End of prog
The test.txt file disappears after I refresh the C: folder.
So the values for snum1, num2 and num3 are all wrong, as if the file was not read correctly.
If I put a while fin.good() loop after printf("fin is open "); for that entire block (until printing the values of num2 and num3), then I get
Code: Begin prog C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt fin is open End of prog
How can I correctly read a file that is only created during runtime?
How do you create a save file for a game, that is not a separate file? Specifically I am using code::blocks and sfml 2.1 to make a game and it saves to a text file at the moment. My problem is that it is very easy to modify the text file, and it is annoying to have to copy and paste several files if you want to use a copy of the game. I have a feeling that it may be to do with resource files, but I'm not exactly sure how to get these to work or whether you can modify them dynamically.
I could do the assignment if all i had to do was create a function within one file, call it in the main class, and that would be done with it. no, my teacher wants us to have our main program, a header and a separate class file and create functions in it in which we can then use in the main file.
This is the main file:
#include <iostream> #include "call.h" using namespace std; int main() { int length; //holds the length of the call in minutes int hour; //holds the hour od the day(0-23 military time)
My problem is that the storeElems member function is causing an error saying it is undefined, however there are no errors any where else in the program being reported. I have made several programs involving classes now, all with this three file format and this is the first time that a member function in the main file is being reported as undefined, so I'm not sure what to do.
So I have to read from a file, and store the information in separate variables. My problem is that for some of the information I need multiple words, and for others I don't, so I cant simply store 1 word into a variable and store the next in another in so on. To demonstrate what I mean let me give an example.
Dog Cat Blue Bird Snake White Horse
I am able to store "Dog","Cat","Blue","Bird"...etc in variables but I don't know how to make it so I can store "Dog" in one variable, "Cat" in a second variable. and "Blue Bird" in a third variable. "Snake" would be the 4th and "White Horse" would be the fifth. How can I read a file and manipulate the pointer to grab what I need?
I have program that is supposed to read in a story from an input file and separate the words and output the lines on which the word occurs. It needs to read in another input file that has a list of words (1 per line) to ignore. i.e. skip them when running through the story. This is what I have so far, I've changed multiple things trying to get it running....
Below is my sample code of a C program. I am doing lot of processing, but my issue is I am getting a segmentation fault error in my main when I am putting the file names at the command line and using them. The program works great in Windows, but its giving error in Unix.