C++ :: How To Access Variable In Different Class
Oct 22, 2014how can I make the queue of type pcb
and how to access pid in other clases?
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Visual C++ :: Access Variable Inside Class From Other Class
Nov 9, 2013I am trying to access a variable from another class through another class but it is not returning its "instance"?
Example:
Class View
Code:
...
V3D_Viewer viewer;
...
Class MainWindow
Code:
...
viewer* myView;
myView = new viewer();
...
Class Test
Code:
...
MainWindow window;
window.myView->setBackgroundColor(WHITE);
...
I am new to c++ references and pointers,
C++ :: Access Private Data Of Base Class Without Access Modifier
Sep 9, 2013if we don't provide the acces modifiers for base class and we need to manipulate the private data of base class in derived class. Is there anyway to acces the private data members? Here's a coding example
class A {
private :
int a;
};
class B : public class A {
public :
void displayA() { cout<<a<<endl; }
};
how i can acces the a of base class A in derived class B without acces modifiers.
C++ :: Why Can't Access The Variable
Jul 17, 2014Code:
#include <iostream>
using namespace std;
void f();
extern int x;
int main() {
[Code] .....
x is declared outside the functions and defined inside main(). Then why this code produces a compile error?
x is already declared so it can be used in f(); and when I call f(), x is already defined. Then why can't f() sets the value of x (in main) to 10?
C++ :: Cannot Access Private Member Declared In One Class But Can In Another Class
Sep 4, 2014So I have an ImageManager class, Board class, and Box class. In Board.h I can declare ImageManager imgr; and in Board's constructor I can use imgr and its functions and such. However, in Box.h when I try and declare ImageManager imgr; I get the error "cannot access member declared in class ImageManager". Both declarations are under private, and exactly the same, but one doesn't work. Also, is there a way to only have one instance of ImageManager?
View 19 Replies View RelatedC :: Variable Access Across Multiple Files
Sep 7, 2013I was trying out programs based on extern and as i understand, this is useful when accessing variables across multiple files having only one definition. But i tried a simple program as below without "extern" and thing seem to work when i expected it would fail during linking process
Code:
file5.c
1 #include <stdio.h>
2 #include "var.h"
3
4 int main() {
5
6 printf("
File5.c a = %d", a);
[Code] .....
As i have included "var.h" in all header files without extern, "int a" would be included in both the .c file and during linking, compiler should have thrown a warning or error message but it compiles file without any issue. Shouldn't var.h have the following "extern int a"?
C++ :: Access Private Member Variable
Apr 3, 2013I've created a class called Voter with a private member variable ID, also I have a variable in my main function to be ID as well. I'm trying to compare the two ID's but when I do so:
if (ID == V.ID)
I get the error - 'std::string Voter::ID' is private within this context.
I know that because it's private I can't access it, but how do I?
C/C++ :: Access Variable Using Extern In A Particular File
Sep 2, 2013I have 3 files: f1.c f2.c and f3.c
I have declared variable int a; in f1.c and int a; in f2.c.
Now I want to use the variable int a; in f3.c . But this variable corresponds to the variable in f2.c .
C++ :: Access Variable Updated In One To Another CPP File?
Dec 18, 2012I have two cpp files.I m updating a value of an integer in one cpp file and i want to perform a specific function in the second file as per to the value updated in the first file. ie I m initialing the variable in the constructor. I have two buttons in the first cpp file. On clicking the first button I m updating the variable as 1 and on pressing button two , I m updating the variable as 2. I m retrieving this variable in the second cpp file with respect to the object created for the class in the first cpp file.
The problem is that i m not able tot retrieve the updated value in the second file. only the initialized value is being retrieved. neither 1 nor 2 is updated.
C++ :: Access Variable From Other Scope Without Global Declaration?
Aug 8, 2013Code:
#include <iostream>
using namespace std;
void f() {
int x=17;
//cout<<main::y<<endl; i want to access y from main scope
}
int main() {
int y=23;
//cout<<f::x<<endl;
I want to access x from f scope is there any way for this without global declaration? specially about function scopes...
C++ :: Access Enum Class And Its Values Outside Of The Class
Apr 23, 2013I cannot wrap my head as to how to access my enum class Azimuth.
Code: #ifndef BOUSOLE_H
#define BOUSOLE_H
#include <iostream>
#include <string>
#include "StringHandler.h"
class Bousole{
[code]...
And here is where I am trying to access my enum for testing/understanding purposes
Code: #include "Bousole.h"
using namespace std;
int main (int argc, char *argv[]){
cout <<"Start bousole" << endl;
Bousole b;
[Code] ....
C++ :: Storing Variable Size Pointers Array As Class Variable
Mar 2, 2013This problem is best explained by looking at its output below. I stored 15 different values but when retrieved some are wrong.
#include <iostream>
using namespace std;
class A {
public:
int ** pointer;
[Code] ....
I need to store and retrieve the 15 different values correctly. How to solve this? The main thing is, I need to store the pointer in class A objects.
C++ :: Variable Belonging To Base Class - Tell Compiler Consider This To Be Derived Class?
Oct 12, 2013I have an example where I have a variable belonging to a base class, but I would like to tell the compiler that it actually belongs to a derived class. How can I do this?
// base class: R0
// derived class: R1
// see function SetR1 for the problem
class R0 {
public:
int a;
[Code] .....
C++ :: Can't Access A Function In Other Class
Nov 24, 2014I am essentially trying to get a value from a 'Matrix' that is created. Using a function in the class where the matrix is created. But when trying to do this I get the error: Call to non-static member function without an object argument in this line when trying to call the function:
Matrix::get(sizeR, sizeC);
C/C++ :: How To Access Field Of A Class By Name
May 2, 2012class myCls{
int x;
};
and then I create:
myCls c1;
and now:
is there way that I go like: cout << c1;
not overloading << operator;
and it shows me a value of c1.x?
just wanna replace c1 with that value;
I need sth similar to indexer from c#.
C++ :: How To Access Pointer To Class Member
Jan 10, 2015I have the following scenario :
Code:
class test {
public :
int num;
};
int main() {
test t1;
test *ptr = &t1;
int test :: *mem_ptr = &test::num;
}
I need to access mem_ptr (pointer to a class member) through :
a. object (t1)
b. pointer to the object (ptr).
How can i do that ?
C++ :: Access Another Library (DLL) Which Has Same Class Name And Method Name
May 27, 2013I have 2 c++ libraries called "Lib1" and "Lib2". Both libraries have same class called "Total.h and Total.cpp"
I want to access lib1 class in lib2. since it has same class (i.e same header file), i couldn't refer lib1's members in lib2.
Lib 1 :
Total.h :
class Total {
public:
static void Test(double);
[Code] .....
How to access another library which has same name and how to add header file ?
C++ :: Access To Private Member Map Outside Class
Oct 24, 2013This question is more from a design point-of-view rather than coding it to be a fully functional.
So here it goes:
I have multiple files which each require their own object of same class type (ref. First Class). File contents are read from a file to a unordered_map<std::string, std::vector<std::string>> which is either private or protected member inside First Class. First Class does not need any public functions to add, remove or change the data during runtime, but changes are only being made by checking if the file size has changed during the day, if the size is not equal to the last check, map gets updated.
Now, I have a Second Class which is a data handler class. It has public member functions with arguments that needs to be get from First Class's unordered_map using const_iterator. Which way to go with design and implementation.
I know there's two methods to do this. Re-doing handler class is also not out of the question. These two methods I'm aware of are:
1. Declare these maps to local scope, build few global functions and here we go. (Probably the easiest way.)
2. Create public member functions to a First Class which either return a pointer or a reference to a protected/private member. (I'm under the impression that I really shouldn't be doing this because of a bad coding practice.)
Note that I don't need any code here, just some other point-of-views regarding the subject itself for learning better coding practices.
C++ :: Class Data Member Access?
Jul 5, 2013I have some doubt regarding class data member accessing in another file.Follwing code showing error.
class A://file a.cpp
{
public:
int add;
int sub;
};
//file b.cpp
extern class A
void cal()
{
A::add=A::sub;
}
C++ :: How To Access Virtual Base Class
May 4, 2013How can I access the virtual base class? This is a practice exercise from c++ primer plus 6.
The problem is that the name becomes No Name instead of the name specified when creating the gunslinger, I don't know how I can call the virtual base class explicitly
Output,
#ifndef PERSON_H_
#define PERSON_H_
#include <string>
#include <iostream>
#include <cstdlib>
using std::string;
class person
[code]....
C++ :: Get Access To Functions Of A Derived Class
Jul 11, 2013I have a big problem with searching a solution for getting access on getters and setters of the derived classes of an interface.
Interface:
class IfParam
{
public:
IfParam();
};
Now I have a derived class for each needed datatype. E.g.
class Int32Param: public IfParam
{
public:
Int32Param();
Int32Param(IfParam* l_param);
int getValue();
void setValue(int l_value);
private:
[Code]...
My Problem now ist getting access to the getters/setters over the interface. I wish I could initialize the Params like this:
IfParam* param = new Int32Param();
param.setValue(12);
IfParam* param = new StringParam();
param.setValue("String");
But to have access to the getter/setter I have to declaire the functions in the interface as generic functions. But how? I tried to use temlates, but then i have to declaire IfParam as IfParam<int>. Thats a problem because in my original program I do not know which TypeParam the IfParam interface will be initialized with when I create the pointer.
C# :: How To Access Form Method From Another Class
Jan 7, 2015Basically am trying to reference a method in a my Form1 class into another class. So far I have tried multiple different methods to try and access the method but have not managed it so far. Both classes use the same namespace. The part of my form class that I am using are as follows:
public class Form1 : Form
{
IContainer components = null;
private ButtonPanelThread p1, p3, p4;
[Code]....
C# :: Unable To Access List Class
Mar 3, 2015how would i access the list created,i should be able to access the list from all other class, adding to it update ect ect.
class test2
{
public string FirstName{ set; get; }
public string LastName { set; get; }
public string Location{ set; get; }
private List<test2> myList = new List<test2>();
public override string ToString()
[code]....
now in a seperate class how would i view the item (print in console) and edit 'mike' location to XYZ.
C++ :: Access Other Members Within Same Nested Class?
Jul 12, 2013It's hard to give a precise title but here is the question in detail: I have a class, something like this:
Code:
class classA{
public:
void fnA();
...
};
and another class that contains objects of classA:
Code:
class classB{
public:
classA A1;
classA A2;
classA A3;
vector<classA*> vA;
...
};
classB B1;
Now is it possible to access B1.vA from B1.A1.fnA() through some kind of pointer chain like this->parent->vA ? If so
C++ :: Cannot Access Private Member Declared In Class
Aug 22, 2013I have a method:
int filetodb(std::wstring szwf, SQLHANDLESTR *h);
I want to use it, in a thread.
std says, use thread, as:
std::thread second (bar,0); // spawn new thread that calls bar(0)
How can I do this, for my method, that uses more than one, i.e., two, parameters?
My code is:
std::thread thread = std::thread(filetodb, filesP->at(i), h);
compiler says:
Error10error C2248: 'std::thread::thread' : cannot access private member declared in class 'std::thread'c:program files (x86)microsoft visual studio 11.0vcincludexmemory06061ConsoleApplicationa
How, can I do this?
C++ :: Nested Class Vector Index Access?
Mar 22, 2014Is it possible to pass the vector index '4' to the Height() function without passing it as a parameter of the function.
Basically, I'm trying to eliminate using 4 twice... what I'd LIKE the statement below to look like is this:
gx.Cell[4].Height();
The only way I can figure out how to get it to work is like this...
class grid{
public:
class CELL{
public:
int Height(int index); //returns the height of this cell
[Code] .....