A file is created but its empty. And when I first create an entry and then display all the entries, it does nothing.
#include<iostream>
#include<fstream>
#include<iomanip>
#include<string>
using namespace std;
class comp {
[Code] ....
I started making something for my class and the thing im getting stuck with is this function:
void ucitajOdgovore(string asocijacija[21]){
int brojac=0;
ifstream fajl;
string putanja;
/*srand(time(NULL)); int random=(rand() %5) +1;
switch(random){
[Code] ....
In the main, i pass real string array "asocijacije" in function which i use in it, and when i use it after this fun. i get an empty array. Its like it didnt happend and i cant see where i went wrong.
I'm having a problem filling a vector from a file. Basically, it is adding an empty element at the end. I'm new to Qt and haven't worked with file streams much so how to stop the stream before it adds the extra element.
void gui::get_data() {
mileage.clear();
QFile file(file_label->text() + ".txt");
QTextStream in(& file);
float m;
float g;
QString d;
[Code] ....
But, if I add another element to the vector and write that the file look like this.
//file after adding element
132654 0 02132014
132654 0 02132014
0 0
132998 22 02202014
I have it set to append at the moment so that is why the first line is repeated. I figure the problem is with if(in.atEnd()). I could fix it by deleting the last element right after adding it, but that seems like more of a hack than anything else.
I am new in c programming. I want to write a function that will count the empty line of the file and display the content.
/* ***************************
** creator: firstprint *
******************************/
#include <stdio.h>
/* function that will identify if line is empty or not */
is_empty(char *buffer) {
while(isspace(*buffer)) buffer++;
if(*buffer==0x00) return 1;
[Code] ....
I am writing this program that is supposed to read a file, put the data into an array, alphabetize, count how many times each word appears and print to an output function. I posted before on how my program had an error when I ran it but I have fixed that. Now my outputArray file is empty. It gets created but there's nothing in it.
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
using namespace std;
//global to this file
[Code] .....
i have this vector:
#ifndef new_thing_Inventory_h
#define new_thing_Inventory_h
#include <vector>
#include <string>
using namespace std;
class Inventory {
[code]....
so i know i need to use .push_back or .pop_back, but the program im using dosn't even recognize that inventory is a created vector.
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?
We have been assigned to create an iTunes library. Everything compiles in my other .h file but my main is not happy with my object declaration. It keeps stating "primary expression before '{'". Here is my main code:
#include<iostream>
#include<string>
#include<fstream>
#include"myTunes.h"
using namespace std;
//function protocols
void read(string);
[Code] ......
This code:
#include <iostream>
class Foo {
};
int main() {
Foo foo;
std::cout << sizeof ( foo ) << std::endl;
std::cin.get();
return ( 0 );
}
produces this result: 1
Why is the size of an instance of Foo 1, although it doesn't have any member variables?
what is the empty state of queue?
View 5 Replies View RelatedIt has been a few years since I have had to do this, but I need to declare a method in my base class, but produce no code for it. Then when this library is used by my second project I will derive a class from this base class and put the code into it there. How is this possible? I used to know how but do not remember how now.
The library is a static library designed for linking with both 32bit and 64bit Windows applications to handle a lot of the tedious stuff with Windows programming. The method in question handles specific command inputs. However, since each program that uses this library will have different uses for these commands, I want to leave it up to the user to code their own handling, but require it to be coded in the derived class.
So this is my working code with sql i want convert it so i can read it from xml, basiccl i need to fill empty list with xml column BrivDat..
var connStr = @"Data Source=(LocalDB)v11.0;" +
@"AttachDbFilename=C:dbaseAdaPlus.mdf;Integrated Security=True";
List<DateTime> Holidays = new List<DateTime>();
using (SqlConnection conn = new SqlConnection(connStr))
using (SqlCommand cmdd = new SqlCommand("select * from Brivdienas", conn))
[Code] ......
I have a doubt related Size of empty structure. I know the answer of empty structure is "0".
How and why the Result got ZERO..??
I am writing a c++ program in Linux.. I am reading a line from commandline at run time using "getline(std::cin,str);". now, what i want is if i left the commandline as idle (terminal as idle), then i want to know that the commandline is empty... is it possible ???
View 4 Replies View RelatedSo I was wondering if I were to empty the elements of a stack into a queue, but i only wanted to empty the even numbers or the odd ones. What would the if statement be to accomplish this. Im guessing for even it would be something like if(number % 2!=0)? What about for odd?
View 2 Replies View RelatedI wrote a template function which use dynamic array as parameter. But if parameter is a empty array, it have compile error.
code:
#include <iostream>
int arry[] = {1,2,3};
int empty_arry[] = {};
[Code]....
compile error:
[zengchao@cmcc-server2 ]$g++ test.cpp
test.cpp: In function ‘int main(int, char**)’:
test.cpp:16: error: no matching function for call to ‘array_parameter(int [0])’
program im creating that is a Mediastore. I have 3 forms one start form where you choose which form you wanna go to Lager or Kassa are the two choices. in these forms i have 1 listbox each that share the same Data. In my Listboxes i have objects of a class called produkts that consist of 3 variables Name,SerialNumber and Price. When i have added these objects to my listbox and they are showing i wanna be able to use my "go back" button to go back to my orginal form where i choose which form i wanna go to and then go to eather my Lager form or my Kassa form and the items are supposed to still there however that is not happening for some reason.
public Lager()
{
InitializeComponent();
}
[Code].....
I am new to c++ and have started creating a dummy program to perform a simple task of writing a few strings to the console, which are first generated using random generation. When I execute the code, an extra line for each generated object appears in the console.
int gemNum;
cout << "This program calculates the value and type of gems
";
cout << "Please enter the number of gems: ";
cin >> gemNum;
vector<int> gemVector(gemNum);
vector<int> gemCollection = fillGemCollection(gemNum);
vector<int> gemSort = sortGems(gemCollection);
vector<string> gemResult = finalGemValue(gemNum, gemSort);
for(int i = 0; i<gemResult.size();i++){
string gemString = gemResult[i];
cout << gemString << endl;
}
This program calculates the value and type of gems..Please enter the number of gems: 4
10 hematite
40 carnelian
60 onyx
120 silver pearl
Press "e" and enter to end program
How do I use 3D graphics .obj files created with UDK in a C++ project?
View 1 Replies View RelatedI have tried to implement a much simplified version of boost::compressed_pair.What follows is a partially specialized EBO_pair<T1, T2> class template, written in C++11.The first type T1 is constrained to not be empty.The second type T2 may or may not be empty.
#pragma once
#include <memory>
#include <type_traits>
#include <utility>
namespace dsa
}
[code]...
Edit: added non-member swap() function template.
I made two dimensional array to represent my (game) inventory. Slot is empty if its value is 0 and 1 if not.
Now i need to find if i can put new item in my inventory that can take up 4x2 slots. I tried this but it doesn't work as i expected:
#include <iostream>
int main() {
const int inventorySlotRows = 5;
const int inventorySlotColumns = 5;
int arr[inventorySlotRows][inventorySlotColumns] =
[Code] .....
I have two classes, one class requests another class to populate a vector with some data using getAvailableStreams() method:
vector<AutoRefPtr<ManifestStream> > availableStreams;
std::cout << "now asking for streams." << std::endl;
manifest->getAvailableStreams(&availableStreams);
std::cout << "got so many streams: " << availableStreams.size() << std::endl;
The other class passes another pre-populated vector back:
virtual RESULT getAvailableStreams(std::vector< AutoRefPtr<ManifestStream> >* availableStreams) {
availableStreams = static_cast<std::vector< AutoRefPtr<ManifestStream> >* >(myStreams); //myStreams contains 1 stream
I'm also adding a stream here directly just for testing purposes:
ManifestStream stream2;
availableStreams->push_back(AutoRefPtr<ManifestStream>(&stream2));
std::cout << "calling getAvailableStreams. Giving so many streams: " << myStreams->size() << ", " <<
availableStreams->size() << std::endl;
return result_OK;
}
If I run the code, I can see the following logs:
Now asking for streams. Calling getAvailableStreams.
Giving so many streams: 2, 2
got so many streams: 0
Why am I getting 0 streams when I exist the method? I just had 2 streams in availableStreams while I was inside the method, where have they disappeared?
Use your language’s native queue class to write the following program: create a class, Patient. The class has 2 members: name of type string; wait_time, a non-negative integer. Read definitions of patients from a file and add the patients to a queue. Write a loop that dequeues a patient from the queue and then decrement the patient’s wait_time. If the patient’s wait time is greater than 0, then the program enqueues the patient again. Otherwise it discards the patient. The loop continues until the queue is empty.
Header File
Code:
#include <string>
class Patient {
public:
Patient();
std::string name;
int wait_time;
bool empty() const;
[Code] ....
I am developing a small game using MFC in which the game options like new game, save, open, exit etc. can be selected from the menu as well as from the buttons inside the window. I have no problems with the menu but the buttons do not seem to work at all.
The buttons are created at runtime using CButton class. To associate the buttons with the corresponding functions, I just used the same resource ID for the buttons as the menu options, but that did not work. When I click on the buttons, nothing happens. If I assign different resource IDs to the buttons, how do I handle the message map entries? Do I have to write different message map entries for the menus and the buttons while their function is exactly the same?
I have declared an array like:
/***********Creating an m*p array**********************/
B = new int *[m];
for(row=0;row<m;++row)
B[row] = new int[p];
How to find the number of elements in it?
The statement
cout << "number of elements in array B equals " << sizeof(B) << endl;
returns 4 each time the program runs
Reading Effective C++ by Scott Meyers, and Item 16 claims that when an array is created, the compiler reserves a block of memory at the very beginning to indicate how many objects are in the array.
n = number of objects
|n|index0|index1|...etc
Scott Meyers wrote:This is just an example, of course. Compilers aren't required to implement things this way, though many do.
Supposedly, this how delete knows how many objects to destruct. And if you were to do something like:
int* foo = new int;
//Stuff
delete[] foo;
Then delete would interpret the first block as the number of items to destruct, then continue on and destruct that many blocks of memory onward, causing UD behavior.
Is there any truth to this?