I want my function to take 'fstream' object as an input, so the program looks like this:
Code:
#include <fstream>
using namespace std;
void test(fstream a){
a.open("test2.txt");
a << "123" << endl
[Code] ....
But I get error: 'std::ios_base::ios_base(const std::ios_base&)' is private|
This is supposed to check for valid input
if(((c.integer < 0)&&(c.numerator < 0))||(c.denominator<=0)) {
c.integer = 0;
c.numerator = 0;
c.denominator = 0;
}
if((c.integer>0)&&(c.numerator<0))
[Code] ....
And it does just fine, until it's passed into a function, then it doesn't work:
void validInput(Mixed a) {
if(((a.integer < 0)&&(a.numerator < 0))||(a.denominator<=0)) {
a.integer = 0;
a.numerator = 0;
a.denominator = 0;
[Code] ....
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 have a Qt classes as follow:
Code:
class Vehicle {
public:
void AddData(QString str, Data* data) {
_myDataMap.insert(str,data);
} virtual void Init();
[code].....
My questions are:
After the main function called d1->Modify; the data stored in _myDataMap will get modified too.
What is the more appropriate way of passing the Data through AddData in such case?
If i do AddData(const Data & data), i will not be able to use inheritance of Data, i.e passing a subclass of Data to AddData.
Ive used a similar approach to extract data from a txt file before, however now it seems to crash when i get to the load, below is the code with a NOTE next to where it crashes. This is homework so no code but just information on why it was working for one dataset but not his new one.
/*
The purpose of this program is to read in data and sort with selection and insertion sort. It will read data from file and write to a new file the sorted data
*/
#include <iostream>
#include <fstream>
using namespace std;
bool openFile(ifstream&);
[code].....
I'm working on a program which creates data and saves it into blocks (different files), then reloads and converts it all. the .ftl file saves properly, but for some unknown reason, it won't let me open it for input after.
Here's the significant code:
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
stringstream filename;
stringstream newfilename;
string Filename;
[Code] ....
setblock will typically = 3, but for testing purposes is set to 1. this really has me confused. the compiler i'm using is Dev-C++ 5.2.0.1 on xp. i have tried pausing the program after the output file is closed, confirming the file has been created in the proper directory before continuing but still fails the .is_open() check.
I am writing a program for a poker game.. I created a class to get cards and create deck.. the problem I am having now is how to deal 5 cards to an array to ve evaluated later. I want to call the array player1[5]. I tried to use pointer but I get the following error
#include <stdlib.h>
#include <iostream>
#include <ctime>
#include <algorithm>
using namespace std;
const char* FaceString[13] = {"Ace", "2", "3", "4",
"5", "6", "7", "8",
"9", "10", "Jack", "Queen", "King"};
[code]....
I've been working on a little project and hit a snag. I'm using nodes for a queue and stack class that were created using an existing list node class. I create an object for a student class and I want to enqueue that object.
int main() {
Queue sLine;
Customer stu;
Queue<Student &>
cLine.enqueue(cust);
}
That's basically the coding of it in main. However when I follow the error which says uninitialized reference member ListNode<Student& info>::data;
#ifndef LISTND_H
#define LISTND_H
template< class T > class List;
template< class NODETYPE >
class ListNode {
friend class List< NODETYPE >;
[Code] .....
What I may have been doing wrong? Trying to work within certain contexts.
Code:
void lexer(ifstream& inputfile) {
string line;
getline(inputfile,line);
[Code] ......
I am trying to pass input file between two functions. The code compiles but immediately upon running the program, there is a "bad cast" run time error.
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.
void InputFileOpen(ifstream &inFile) {
string file_name;
if(!inFile.is_open()){
cout<< "Enter the input file name: ";
cin>> file_name;
inFile.open(file_name, ios::in);
[code]....
Code:
#include <Data.h>
int main(int arg_count, char** argv) {
if(arg_count!=3){
cerr<<"Files misisng
";
exit(1);
[code]...
This actually should work, because it is passing address of polymorphisms object.I have tried changing prototype of test in Data.h, but failed.passing object address/pointers in C++.
I am having an issue with passing an ifstream object to functions. Here is the code:
Code:
#include <fstream>
using namespace std;
void otherfunction (ifstream *ifs) {
...does stuff, like ifs->open(), then reads from the file...
}
int main () {
ifstream ifs();
otherfunction(&ifs);
}
Here is the error message:
Code: error: cannot convert ‘std::ifstream (*)()’ to ‘std::ifstream*’ for argument ‘1’ to ‘void otherfunction(std::ifstream*)’
Why can't I do that? What does "ifstream (*)()" even mean? And I don't want to change the structure of the program. I have reasons for declaring the ifstream object in the main function (because there are actually two functions that need access to the ifstream object -- neither of which is working).
Also, if I change the main function to be this instead:
Code:
int main () {
ifstream ifs();
ifstream *ifsptr = &ifs; //EDIT 2: forgot the ampersand
otherfunction(ifsptr);
}
I get the same error as above. However, if I change the main function to this:
Code:
int main () {
ifstream *ifsptr = new ifstream();
otherfunction(ifsptr);
}
I get all kinds of crazy errors about "undefined symbols for architecture _____". Here is the actual error message from my program (parseArgs is the real name of otherfunction)
Code:
Undefined symbols for architecture x86_64:
"std::ios_base::Init::Init()", referenced from:
__static_initialization_and_destruction_0(int, int)in cchumGBV.o
"std::ios_base::Init::~Init()", referenced from:
[Code] .....
I am trying to pass an object to an inherited clas by a constructor. I am having Cboard my board and i need to pass it to the object Cpawn.
Here under is my code:
main
Code:
#include<iostream>#include "Cboard.h"
#include "Cpawn.h"
#include "Cpiece.h"
void main(){
char location[50];
[Code] ....
This problem just seems really strange to me because it is simple yet for some reason my class cannot pass into another class. The class PASS_OBJECT has a static array (even with 1 element this doesn't work) and when I try to pass this class (after it is initialized) I seem to lose the data inside the PASS_OBJECT. Not only that but even when I declared the class OBJECT with the type of PASS_OBJECT<int> I seem to lose the integer 99. Here's the code, note that if you comment out line 89, 92 and 93 you will notice that line 90 outputs In main 2: 99 just fine but it doesn't otherwise???
#include <iostream>
const int size = 1;
template <class T>
class PASS_OBJECT;
template <class S>
class OBJECT {
[Code] ....
Here is my issue: I am making a simple audioplayer in Xamarin.android but i want every time i change the track to make a crossfade effect. So im using 2 mediaplayers at the same time for the fade. The problem is that im defining one time the players and i pass the player as a parameter like this:
public MediaPlayer player = null;
public MediaPlayer player2 = null;
....
If i have to fadeout the player and start the next one im doing it like this:
if (player != null){
if (player.IsPlaying) {
cts = new CancellationTokenSource();
token = cts.Token;
FadeOut (player, 2000 ,token);
[Code] .....
So my problmem is that player and player2 remain always null. Why? i guess c# creates a copy of player and player2 and use this one. How i can pass a mediaplayer as parameter and always use only player and player2?
This is my question : Define a class named HOUSING in C++ with the following descriptions:
Private members
REG_NO integer(Ranges 10 - 1000)
NAME Array of characters(String)
TYPE Character
COST Float
Public Members
-Function Read_Data( ) to read an object of HOUSING type
-Function Display() to display the details of an object
-Function Draw Nos( ) to choose and display the details of 2 houses selected randomly from an array of 10 objects of type HOUSING Use random function to generate the registration nos. to match with REGNO from the array.
Now I' trying to do this by this way
Code:
#include <iostream.h>
#include <conio.h>
#include <stdlib.h>
class housing {
private:
int REG_NO;
char NAME[10];
[Code] .....
I am trying to pass the entire array of object in DrawNos(). but getting compilation error -
32: 'housing:rawNos(housing * *)' is not a member of 'housing'
48: Structure required on left side of . or .*
What is the problem? How can I pass the array of object in function and use it.
I want to use one median function "selectfunction" to choose one of the 2 other functions at random to pass my 2-dim array to the selected function. There is a problem in the median function
#include <iostream>
#define random(x)(rand()%x) // for random number between numbers of 0 and 1
using namespace std;
void proc1 (int iArray[][2]);
void proc2 (int iArray[][2]);
void selectfunction(int iArray[][2]);
int A[4][2] = {{1, 2} , {3, 4} , { 5, 7} , {8, 1} };
[Code]...
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
[Code] ....
I am trying to pass function as argument to another function. My idea is to write function that can works with any type of array, and for it to be able to compare array items I'd like to use my own compareTo function. But I need to be able to pass function to use for comparing argument.
To say it short I am trying to write my own qsort that would take compareTo as one argument just like original qsort does.
Here is my code
// test.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <windows.h>
template <class T>
int compareTo( T a,T b){
[code]....
and errors
1>d:my documentsvisual studio 2012projects est est est.cpp(29): error C2896: 'void DoSomething(T,int (__cdecl *)(T,T))' : cannot use function template 'int cmp(T,T)' as a function argument
1> d:my documentsvisual studio 2012projects est est est.cpp(8) : see declaration of 'cmp'
1>d:my documentsvisual studio 2012projects est est est.cpp(29): error C2784: 'void DoSomething(T,int (__cdecl *)(T,T))' : could not deduce template argument for 'T' from 'int [3]'
1> d:my documentsvisual studio 2012projects est est est.cpp(21) : see declaration of 'DoSomething'
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_CMD_LINE 500
}
[code]....
The value that opt_rdrct_2 & inpt_rdrct_2 point to are not being passed to opt_rdrct and inpt_rdrct.
How to pass an int that I got from user input into a function to use it. I am trying to print out the words to a string of numbers.
I got the input from user.
I got an absolute value of the input.
I then separate the string into individual digits and name them.
I can print these out.
Then I started my if statement by checking if the original input was zero, and if it is, printing zero and exiting.
Then I an trying to pass the digits into a switch function and this is where I go off the rails.
Code:
#include <iostream>
#include <string>
#include <cstdio>
#include <iostream>
#include <iomanip>
#include <cstdlib>
using namespace std;
[Code] .....
I want to scan numbers in from within a function, but have access to them in main, so I tried using pointers to do so:
Code:
// Path Of Exile socket colours simulation
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
[Code].....
The program asks for to ask the user for how many students there are, and how many strawberries they picked. The farm gets to keep half and the students get to keep the rest.
I am using functions and passing values to one function to another. I know I am making it harder then I need to, but I want to work with functions more and passing values. I figured it was better to practice with simple programs.
Code: #include <stdio.h>
float people(float);
float strawberries(float x);
[Code].....
I want to pass array to function, to fill array with new values and then to print the array in the main. But I have problem because it prints me just array of zeros. Maybe the concept is wrong, I'm new with passing arrays to function.
function:
Code:
void printSum(int *return_array) {
int return_array[3];
int i;
for(i = 0; i < 3 ; i++){
return_array[i] = 5;
Code:
void printSum(int *return_array);
int main {
int m_return_array[3];
int i,j;
for(i= 0 ; i < 3 ; i++){
m_return_array[i] = 0;
} printfSum(start,m_return_array);
[Code]...
I need to pass a 2D array to a function. I want to know, where I may have made a mistake. This is the piece of code that I found on the web, and I am using it to allocate my 2D array.
Code:
signed char allocate2D( int** arr2D, int rows, int cols )
{
int i;
arr2D = malloc( rows*sizeof( int* ) );
if( !arr2D )
return -1;
[Code]....
My main function passes the 2D array to the function
Code: signed char read_root_message_file( int **Root_Messages, int *num ) This is how I pass the array in the main function to the above function:
Code:
int main( int argc, char *argv[] )
{
int **Root_Messages;
...
...
Root_Messages = NULL;
read_root_message_file( Root_Messages, &num_root_msg );
[Code]....
Would this be an example of passing an array to a function??
Code:
void wipe (int theArray[] ) {
int index;
printf("
Inside function wipe() sets each array element back to 0.
");
[code]....
I am following a tutorial and the topic was passing array to function so i tried to do a BMI calculator by myself. I am using code blocks to compile the codes, it is actually working while using compiler's run button. But when I open the exe file, its closing the window after entering the persons' weights and heights. Here is the code
Code:
// Passing array to function example BMI calculator of n person
#include<stdio.h>
#include<math.h>
void assess(float bmi[],int a);
int main(void){
int n,i,j;
}
[code]....