C++ :: Create Header File In Which Can Change Value Of Variables
Apr 12, 2013I just can't seem to find how to create a header file and where I can change the value of the variables. It sounds simple.
View 12 RepliesI just can't seem to find how to create a header file and where I can change the value of the variables. It sounds simple.
View 12 RepliesHow would I change the private variables in the header files and the code in the cpp files for the primary indexes so they use a dynamic array or vector instead. For the primary index, the initial vector size will be 8.
header
#ifndef MY_PRIMARY_INDEX_H
#define MY_PRIMARY_INDEX_H
#include
#include
#include
#include
class PrimaryIndex
[Code] ....
I'm trying to split up my game (about 1300 lines) into header files, but I'm coming up with a problem whenever I try and put a function in a header file, when that function was modifying some variables that were defined before int main in the .cpp. For example:
int variable1 (0);
int variable2 (0);
void increasevariables() {
variable 1 = variable1 + 1;
variable2 = variable2 + 1;
[code].....
If it only modified one variable then I could just pass that variable and the return it:(return variable1 + 1;)But I don't know how to make a function in a header file modify several pre-existing variables. In the actual program, the variables are dependant on each other and the modifying is a lot more complicated, so I'd rather not split it into several functions and run one at a time if there's another way.
I declared 3 private variables in header file.
I try to access one of the variable in its corresponding cpp file but I get an error message saying it's undefined. I did #include the header file. Why is this?
I read in another forum that it is bad practice to declare static variables in a header file? Is that true and if so why.
View 1 Replies View RelatedI need to write a C++ program, that extracts certain variables, x y z, from a file that is continuously being updated x y z. These variables are going to be used to recalculate a new answer.
My question is to see if it is possible to have an include .h file that is always being updated so that I can extract these three variables from it, and always have the newest venison of each variable, so that the answer to the equation is always the newest updated. Should I use fopen or fwrite to do this.
Any good/solid example on how to create a header file?
View 2 Replies View RelatedI'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 >)
[Code] ....
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:
1> Resistor.cpp
1>c:users omdocumentsschoolcomp 220week 2lablab 2.2lab 2.2
esistor.h(11): error C2146: syntax error : missing ';' before identifier 'resistor'
1>c:users omdocumentsschoolcomp 220week 2lablab 2.2lab 2.2
[Code] .....
Here is the first portion of the .h file:
#include <iostream>
#include <iomanip>
#include <Windows.h>
#include <math.h>
#include <string>
class CResistor{
double res1, res2, res3, percentage, Nominal, Tolerance;
[Code] ....
Here is what I did,
Code:
// A.h
const int salary = 1000000;
// B.h
extern const int salary = 1000000;
But I still got multi-definition errors. How should I fix it?
I'm trying to change the values of some instance variables in my Controller Class so that when the user inserts values into main class it changes for Controller.
class Controller {
public:
Controller();
~Controller();
double PCFreq;
__int64 CounterStart;
[Code] ....
The user should be able to choose which foo the want to use. So I create an object of controller in main like this
Controller* con = new Controller()
Now my issues is, when I take user input (an integer) and try to do this
con->choice1 = choice1;
only the object of con's choice1 is = to user input.
However back at the class for Controller, choice1 hasn't received a value.
I can't initialize through Controllers constructor because I get the user input through a switch statement and the range of con would only be as far as the case.
I want to create a welcome text header during the program runs. I wanna keep it at the top while the program is running (like asking for input@ showing output).
EG:
-----
WELCOME
----- //Stay until end of the program
// output/input. "WELCOME" stay at the top
I would like to create an array of struct variables inside a table to avoid using many if/else and/or switch/case statements. I have attached a simple example of what I am trying to do, it doesn't work. For the table "sTablePtr" I see different values than what I set, when I dereference it with a "&" it just shows me the addresses of the variables. However at the end, when I do print out the values, by just using the structs themselves, they print out the values correctly.
My structure declarations must remain a pointer. To be clear, what I am trying to do is have sTablePtr[i] show me the correct values I set, in this case I want the for loop to print out 1, 2 and 3. If there is a different way of doing this, I am open to it as long as I can use a table of my struct variables to avoid many if statements.
#define MAX_CNT 3
typedef struct {
int nNum;
int nCnt;
}sDummy1;
[Code] ....
I need to create a project that create a automated backup of a file.
i will get the file from C:/Folder/file.exe and move for a other created folder, but.. in every time that user make this backup, a folder will be created with year, month and date, like: C/Folder2/2014/April/16:42/file.exe.
I have written my program and it works when I keep everything in the header files, and then have my main. I am now splitting them up into implementation files, but Eclipse keeps giving me errors. It gives me error at every opening brace of the constructor and functions. It says on all of them "Redefinition of (name of constructor or method), Previously declared here." What am I doing wrong, because it works in the header file?
#include "KeyValuePair.h"
template<typename Key,typename Value>
KeyValuePair<Key,Value>::KeyValuePair()
[Code] .....
I am working on an assignment in which i have to perform th following task
myClass itsObject1,itsObject2;
itsObject2=5000+itsObject1;
I have defined overloaded operator as follows in the header file but in the cpp file of the class it gives error.
friend vli &vli::operator + (int &a,vli &obj);
How to define it in cpp file of my class?
I am trying to create a simple interface on console to allow to input some values to some variables. For ex:
int main() {
double a = 1.5;
double b = 2.5;
double c = 3.5;
string x;
[Code] ....
However, I want these three to display at the same time (now they display one by one), and in the console window I can move the cursor between input place of a, b and c with "arrow key" of keyboard.
What is the right syntax for implementing the .cpp of a template class?
Consider this LinkedList.h file:
Code: #include<iostream>
#include"Iterator.h"
template <class T>
class LinkedList {
[Code] ....
How should the implementation for the LinkedList constructor, for example, should look like in the LinkedList.cpp file?
I tried this:
Code: #include "LinkedList.h"
template <class T>
LinkedList<T>::LinkedList<T>() {
// constructor
}
LinkedList<T>::~LinkedList<T>() {
// destructor
}
But the compiler wouldn't accept it.
lets say we have a valid class with full implementation, X. can this class be declared as forward in Y header file:
Code: class X;
class Y{
X* m_X;
}
but still be used as regular in the cpp file?
Code:
#include "Y.h"
#incldue "X.h"
T Y::function(){
m_X->doSomething();
}
visual studio prevents me from doing it , I wonder if the standard also says so.
I wanted to share the value of a variable from Sender Program to Receive after program and want to calculate difference between send and receive. After studying Header file concept I program following three.
Now I am struck. How to to compile? I link all these file. I used following method:
Code:
gcc Sender.c -o Sender Sender.h
gcc Receiver.c -o Receiver Student.h
Then I run Sender and after that Receiver.I per my knowledge, Receiver should give difference but it gives error :
Code:
Receiver.c: In function "main":
Receiver.c:10:42: error: "Send" undeclared (first use in this function)
printf(" Total Receive is %d
",Receive-Send);
Code:
Sender.c
#include <stdio.h>
int Send ;
void main(){
[Code] ....
I have been working a project in C++. I have TTTMain.cpp file that has all the function calls, TTTFuntions.cpp that has all the functions, I have TTT.h file that has all the prototypes and variables and additionally I have Winner.h that has enum class Winner declaration in it. Here is my block of codes:
Winner.h file:
#ifndef winner
#define winner
enum class Winner {
[Code]....
My question is when I compile this gives me error on
Winner gameSquares[] = { Empty, Empty,Empty, Empty, Empty, Empty, Empty, Empty, Empty };
with saying "invalid use of non-static data data member" and It says "Empty was not declared in this scope."
I know calling enum is very very trick.
I am beginner in c++ language. i'm use visual studio 2010 ultimate. the problem is i can't add c++ file(.cpp) and header file(.h).
Here the screenshot : [URL] ....
I made my header file. If cpp file with definitions is in project compiler knows it has to be linked, but if it's not compiler doesn't know. If I include standard library or boost I don't have to manually link cpps. How to do so including my header automatically links cpp? Maybe problem is with something else?I use VS 2013.
View 4 Replies View RelatedMy socket.cpp program got error. it showed "socket.h: no such file or directory". I had put my header file (socket.h) in the same place with my source file.
View 1 Replies View RelatedMy coin/money change code works when there can be an exact change each time, i.e. when the 1 cent option is available. However, when the change options are only $10, $5, $1, 25 cents and 10 cents, it does not give me what I want for instance, I wanted to get change for $237.80, I was expecting to get:
23 10's, one 5, two 1's and 8 dimes. However, the code below is giving me 23 10's, one 5, two 1's and 3 quarters (there is no option left for the 5 remaining cents).how to fix it?
Code:
#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
void change(double cents, int a[]);
int main() {
double Dollars;
double cents;
[code]...
1. Write a program the calculates the volume of a sphere.
Use a define to set Pi to 3.14 and a macro for the formula for the sphere.
V = 4/3PiR3.
In main ask for the radius (R).
Pass it to a function where you calculate the volume and return it to main and print the volume in main.
Use float values. (Save this program as you'll need it later.)
Code:
#include<stdio.h>
void fun (float);
main()
[Code].....