class Base
{
.....
.....
.....
virtual void display();
[code]....
in the above polymorphism why is it called runtime polymorphism when i can say seeing the code itself that display() function in derived gets executed with ptr->display(),so how does it become runtime polymorphism when i could get decide at compile itself ???
How can we calculate tax of vehicle with polymorphism? There are 3 types of vehicles: long, commercial, and private vehicles' classes. There is a common class about all vehicles.
BASE class:
1.Brand and series name (such as Toyota Corrolla, Isuzu etc.)
2.Year of production (you can term it model)
3.Engine size in dm3
4.Owner’s name (including surname) and identity
5.Plate number.
COMMERCİAL :
1.Number of seats (apart from the driver)
2.Data to indicate whether the commercial vehicle is allowed to operate at night.
LONG :
1.The tonnage (max load in tons)
2.Data to indicate whether the long vehicle is allowed to carry goods internationally.
PRİVATE:
1.The class label which can be one of {A,B,C} .
I have been reading up about object oriented programming recently and have come across 'Encapsulation, Polymorphism and Inheritance' as i understand it so far all OOP programs should use these three concepts. So i started thinking how do i get these concepts into my program as i am using WPF C# and i could not really find much good info about how these concepts apply to WPF programs.
Or do these concepts just not work with WPF programs?
if we do a virtual functions(polymorphism) why we need re-declare the functions(when we create a new class derived from other)?
View 10 Replies View RelatedI must overload [] but at the same time I must use polymorphism. I wonder if using polymorphism affects operators overloading since when I modified the first class by writing "virtual":
virtual void mostrarDatos(char*, char*, char*);
virtual void calcularEdad(int);
So I can do the polymorphism, it affects the part of the code where suppose to do an addition:
s=student1+=student2;
t=student3+=student4;
u=s+=t;
if I do that, it shows some strange numbers instead of the right ones. Here is the complete code:
.h
#ifndef PERSON_H
#define PERSON_H
#include <iostream>
using namespace std;
class persona {
[Code] ......
I have couple of objects which are using some amount of methods. Right now my application is not OOP and i am going to transfer it to OOP. So i would create each class for my each object. Almost all methods are in use for each object, the only one thing which is changing some of those objects passing not all parameters inside specific method. I can go two ways one is prepare interface for all methods i got and each of my classes could implement its own definition for it but other way almost all would implement exactly the same methods but with different parameters so maybe its better to create base class then for each object do inheritance from base class (polymorphism). inside base class i can prepare base methods and classes which will inherit from that class would override those methods for requirements they want.
So imagine: You got:
Memory
CPU
Latency
and all of them using mostly all of those same methods (only arguments for one of them could be use different way):
ExecuteQuery()
ExportToExcel()
PopulateDataTable()
PutValueToReport()
Now its better to do like this e.g:
Base class: Stuff
prop: name, id, date ...
methods to ovveride: ExecuteQuery(), ExportToExcel() ...
classes: CPU, Memory, Latency (inheriting from Stuff)
ovveride methods and align its definition for specific class use (remember mostly only passing args are used or not by specific class)
or go with inheritance
Interface SomeMethods
ExecuteQuery()
ExportToExcel()
PopulateDataTable()
PutValueToReport()
and each class would implemet its own definition.
The most important thing is that those every objects mostly using all of those methods and what is diffrence that one object can use all of available parameters inside this method and other one no. What i should do? Go with interface or inheritance and polymporfizm inside base class?
I defined a virtual class and three other classes based on it. I want to use them like this:
int main() {
Dirichlet_t D;
Neumann_t N;
Cauchy_t C;
PDEBoundary_t * B1=& D;
PDEBoundary_t * B2=& N;
PDEBoundary_t * B3=& C;
[Code] .....
but I got two major errors
1: "object f abstract type is not allowed" error.-----why not?
2: "the derived class must implement the inherited pure virtual method"-----Did't I?
Having issues with program to create a shape area calculator with circle square and rectangle. the uml goes as follows:
Where the UML has shape as the abstract class with public area():double, getName():string,and getDimensions:string, rectangle derived from shape with protected height, and width, and a public rectangle(h:double, w:double), followed by a derived square from rectangle with just a public square(h:double), and finally a circle derived from shape with a private radius, and a public circle(r:double).
[URL]
Have linked my program and it is giving me the following compiler errors:
error: 'qdebug' was not declared in this scope line 15 of main
error: cannot declare variable 'shp' to be of abstract type 'shape' line 22 of main
error: expected primary-expression before ')' token lines 29 -31 of main
(note previously had qstring as a header file yet changed to string since I was getting error qstring was not declared in this scope.)
I've been working on this project which inserts data for different types of books lately, and I'm trying to utilize inheritance and polymorphism. The issue I've been having is after I create an object with my MediaFactory, I go to insert data into that type of object, but it won't reach the correct child class. The parent class in this case is MediaData. The class I'm trying to reach is Childrens, and the class that falls in between is called Book. The function I'm calling to insert the information is setData(ifstream&). This function simply places the information from a txt file into an object with the insertion operator.
Right now the program runs into the setData function of Book instead of Childrens. I need Childrens so I can enter all the required attributes (title,author,year). The call to this function is in MediaManager through the function called buildMedia, and my test is running into the case if (type == 'Y'). From there a pointer of type MediaData is created and pointed to a new object returned of type Childrens. I'm using my debugger in Xcode which does show that the correct object type (Childrens) was created.
I've tried a couple things so far. First I created another function called getData. From there I passed in *media and infile (txt input file) into that function, which then passed it right into setData with a pointer to the object and infile in the parameter. That didn't work, so I also tried going back into Childrens and removing MediaData from all my virtual functions and replacing it with Book. I got the same result when that happened; It morphed into Book class instead.
I have a portion of my UML as a reference. Childrens is a Book; Book is a MediaData. I also included all code for MediaManager, MediaHash, MediaFactory, MediaData, Book, and Childrens.
I did not include the operator overloads in the .cpp files to eliminate some redundancy.
//-----------------------------------------------------------------------------
// MediaManager.h
// Manager class for MediaData type objects
//-----------------------------------------------------------------------------
#ifndef MediaManager_H
#define MediaManager_H
#include "MediaHash.h"
#include "MediaFactory.h"
#include "MediaData.h"
using namespace std;
class MediaManager {
[Code] ....
Below code produces run-time segmentation fault (core dumped) when execution reached line 53: delete [] array
Code 1:
#include <cstdlib>
#include <iostream>
using namespace std;
#define QUANTITY 5
class Parent {
protected:
int ID;
[Code] ....
Output of code 1:
Constructor of A: Instance created with ID=1804289383
Constructor of A: Instance created with ID=846930886
Constructor of A: Instance created with ID=1681692777
Constructor of A: Instance created with ID=1714636915
Constructor of A: Instance created with ID=1957747793
A::showID() -- ID is 1804289383
A::showID() -- ID is 846930886
A::showID() -- ID is 1681692777
A::showID() -- ID is 1714636915
A::showID() -- ID is 1957747793
Try to delete [] array..
Segmentation fault (core dumped)
Question: Why does segmentation fault happen in code 1 above?
I am making a very basic parent/child class based program that shows polymorphism. It does not compile due to a few syntax errors reading "function call missing argument list. Lines 76 and 77, 81 and 82, and 86 and 87.
#include<iostream>
using namespace std;
class people {
public:
virtual void height(double h) = 0;
virtual void weight(double w) = 0;
[Code] ....
Here is my error message: Warning1warning C4717: 'getx' : recursive on all control paths, function will cause runtime stack overflow
and here is my code I will Bold the part that is giving me problems!
class point
{
public:
point();
[Code]....
While running a Doc/View SDI, is there any way to switch from text mode to rtf mode during runtime? Search reveals nothing.
Say I have an editor and I want the app to use text, I can set the ctor as follows.
Code:
CEditorDoc::CEditorDoc() {
// TODO: add one-time construction code here
m_bRTF = FALSE;
}
But once I've done that and compiled the app, while it's running, is there a way for the user (or programmer) to change the mode back to RTF? One solution that occurred to me is to use 2 document classes, but that's a hassle.
I can not set the size of my array while running porgrama. Is there any way to do this in C + +?
---- code ------
#include <iostream>
#include <string>
using namespace std;
[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 downloaded Oracle instantclient-basic-nt-12.1.0.1.0.zip and instantclient-sdk-nt-12.1.0.1.0.zip and extracted both to c:oracle I then went into visual studio 2013 and created a Win32 Console application with all default parms.
I then went into project -> properties -> C/C++ -> General -> Additional Include Directories and added my include path C:oraclesdkinclude
I then went into project -> properties -> Linker -> General -> Additional Library Directories and added C:oraclesdklibmsvcvc11
I then went into project -> properties -> Linker -> Input -> Additional Dependancies and added oraocci12.lib
The program compiles but when I debug i get a RUNTIME error that says "The program can't start because oraocci12.dll is missing from your computer. Try reinstalling the program to fix this problem. But I know the file exists in C:oraclesdklibmsvcvc11oraocci12.lib
This is the code if it makes a difference
Code:
#include "stdafx.h"
#include <iostream>
#include <occi.h>
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
[Code].....
I've come to a point where I want to manipulate an image file at run time or with pre-determine sizes and have to be applied when the windows is moved or through in program options.
I know I can do the applying part. However I am a little unsure of how to tackle the image manipulation. I want to make it so that it is not os dependant. So I know I can not rely on any os functions. The only other thought that came to mind was to deal with the video card itself.
So the main question after all of that is said and done. How is c++ able to interact with the video card directly for images? Or if there are existing function I can use. How do they do that? If I can use existing function I would like to be able to manipulate it myself.
I have this TicTacToe program that needs finishing. All the code is finished, but I'm getting runtime errors. It is printing out junk values from my array when they should be empty.
//Player.h
#include <string>
#include "TTT.h"
using namespace std;
class Player {
[Code] .....
//This is a screenshot of the output. [URL] .....
Need fixing code to calculate male and female body fat percentages. Should a switch structure be used? Here is what I got:
#include <iostream>
#include <cmath>
#include <iomanip>
#include <string>
using namespace std;
int main() {
int bodyWeight;
double bodyFatPercent,bodyFat;
[Code] .....
I am getting a strange runtime error when trying to run my hash table program. I have it separated in 3 separate files. I believe I have narrowed down where the error is occurring. It is either happening in insert(const &string s) or in the implementation of vector<list<string>> ht. I would appreciate some input. This is the implementation of insert():
void HTable::insert(const string &s) {
int h = hash(s);
cout<<h<<endl;
list<string> &tempList = ht[h];
[Code] .....
And it is giving me some sort of compilation error saying I cannot convert a type string to type list.
Right, I'm making a game and I'm not sure how I'm going to do this:
On Skyrim (for example; there are thousands of others), when you equip a helmet, it appears on your character's mesh.
How do they do that? Do they modify the mesh, or simply render the helmet at a location which makes it look like it is on their head, or what?
I'm doing a project. And I want to give the user the ability to write methods just like you would regularly in c# during runtime and then use them during runtime. Is such thing even possible? If so how?!
View 12 Replies View RelatedI made a winForm with a button on it in the Designer (VS 2010 C++).
But when I run my app, the button does not show on the form.
The button visible property is set to true.
I somewhere read "You cannot initialize a structure like that at run time."
Example:
struct item_info {
char itemname[15];
int quantity;
float retail;
float wholesale;
[Code] ....
But if you want to assign values at run time then you have to do it manually like:
strcpy(item[0].itemname, "rice");
item[0].quantity = 10;
item[0].retail = 40;
item[0].wholesale = 30;
I tried in internet but am unable to know the differences. I want to know the difference between those two in terms of run time and compile time. Explanation required also for below one. Is this run time or compile time? How does we actually decide which is run time and which is compile time!
struct item_info {
char itemname[15];
int quantity;
float retail;
float wholesale;
//int quatityonorder;
[Code] ....
I am looking for a way to declare variables at run time which being a static language shouldn't happen. I will explain my situation.
I am upgrading a legacy program that modifies executables (non malicious). I am trying to add 64bit support.
It is a huge project and I understand the majority of it but my issues with how it handles the input data.
It has a struct that certain parameters of the input file is loaded into:
Code:
typedef struct DATA {
DWORD Size;
IMAGE_NT_HEADERS32 Headers;
} _DATA; *PDATA
etc, etc its a huge list.
My problem lies in the fact that I need to change IMAGE_NT_HEADERS_32 to IMAGE_NT_HEADERS64 at runtime.
That DATA struct gets called at least 110 times during runtime.
How I might tackle this? Having a conditional statement repeated that many times seems ridiculous.
When I am giving elements for row 2 ,program crashes .it says access violation.
Code:
#include<iostream>
#include<vector>
#include<string>
using namespace std;
void matrix_init(vector<vector<string>>& v)
[Code] ....