C++ :: Virtual Functions - Calculate Carbon Footprint For Car / Building And Bicycle
Apr 13, 2014
I'm writing a program that calculate the carbon footprint for car, building, and bicycle. i have three classes building, car, bicycle. class called carbonfootprint have the pure virtual and should have the formula, but i didn't find it. having a little bit hard understanding some requests. like,
• Write an abstract class CarbonFootprint with only a pure virtual getCarbonFootprint method. Have each of your classes inherit from that abstract class and implement the getCarbonFootprint method to calculate an appropriate carbon footprint for that class.
• The main() function in the given program creates objects of each of the three classes, places pointers to those objects in a vector of CarbonFootprint pointers. You need to iterate through the vector, polymorphically invoking each object’s getCarbonFootprint method.
// Test program for CarbonFootprint and implementing classes.
#include <iostream>
#include <vector>
using namespace std;
int main() {
vector< CarbonFootprint* > list;
// add elements to list
[Code] ....
View 4 Replies
ADVERTISEMENT
Jan 31, 2014
I was reading about the CRTP, and I can't for the life of me understand it's advantages over virtual functions.
Unless you're coding embedded systems, and can't afford the few extra bytes for the vptr, or coding something requiring high-performance, where every nanosecond counts, I just don't see why the CRTP is so attractive. It just adds more text and forces every user class that wants to use the CRTP'd hierarchy to become a template class.
I tried implementing my Functor hierarchy with the CRTP instead of virtual functions...All it did was clutter my files with angle brackets and made the whole thing look very ugly.
View 14 Replies
View Related
May 2, 2014
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 Related
Oct 14, 2013
I try the functions pointers too, but without success. I understand the objects are the way for work with class's. until here fine. But why i can't change the virtual functions from an object? is there anyway for do it? Ican't do, outside of classfunctions, these code:
#include <iostream>
using namespace std;
class test {
public:
virtual void created(){};
[Code] ....
How i can validate these line:
void a::created()
???
View 2 Replies
View Related
Oct 19, 2014
I recall when I first started playing with C++ I was told that you should never use virtual functions unless you absolutely cannot think of a better way to do whatever you are attempting. This is something I have tried to stick to over the years - and indeed is probably why I have never used inheritance or polymorphism much in my own programmes.
However, I notice through a great deal of the code examples offered to questions here and even over on StackOverflow that commentators show no hesitation to recommend code that involves virtual functions. More so, I have even seen several instances here where - what I was taught as, but they may well have a different official name - 'pure virtual functions' (those with definitions inside a class of something like virtual int function_name(void)=0) are demonstrated and I was very clearly taught to avoid those like the plague.
I was wondering therefore has the official thinking changed since the middle nineties on when - and even whether - to use virtual functions in your programmes?
View 9 Replies
View Related
Feb 15, 2013
Is it possible to do something like this:
class A //parent {
public:
virtual void DoSomething() = 0;
};
class B : public A //child {
public:
void DoSomething(string s) override;
}
Where the child member function overrides and changes the parents member function.
I need to pass an array of key states to the Controller class' Update() function but don't want to send it to every class derived from Object (like Controller).
Is this possible or do I have to overload the original Update() member function (but I would need to define the method in Object then (i.e remove the pure virtual function (=0)))
View 4 Replies
View Related
Jan 26, 2013
when I should use pure virtual functions.On the one hand, "TOY" for example should be an abstract class since theres no such thing as "TOY" , there are "toy cars", "toy fighters" etc , but on the other hand I need to force it somehow to be abstract since theres no really a function that any toy should have and implement on his own way (except PRINT maybe).
when I should REALLY use pure virtual functions? And if I want to avoid people from creating TOY objects (for example), the only way is PURE virtual functions. right?
View 4 Replies
View Related
Sep 11, 2014
So I have 2 seperate base classes, (note that I removed the variables and functions that do not relate to the topic) Object.h
class Object{
public:
Object();
~Object();
[Code].....
The error I get is saying I am calling a function declared with one calling convention with a function pointer declared with a different calling convention and this makes perfect sense because for some reason, the function pointer is pointed at the virtual function Object::update but I can't figure out why and how to make it point at the virtual function Drawable::getImage.
Also, the virtual update function is called in a different place just before this and works correctly.
View 6 Replies
View Related
Aug 7, 2013
I'm working with inheritance and pure virtual functions, and I want to overload an output stream operator. However, every time I run the program I get this: 0x7fff00ee98c0.
I'll include a base class and a derived class so you can see what I'm talking about.
Base:
#include <iostream>
using namespace std;
#ifndef _Insurance_h_
#define _Insurance_h_
[Code]....
The application is something like this (I'm assuming the user has already inputted the name, salesperson, make, model, etc):
#include "Auto.h"
#include <iostream>
using namespace std;
#include <vector>
vector<Insurance *> sales;
[Code] .....
View 4 Replies
View Related
Nov 26, 2014
I'm currently involved in an embedded (cortex M3) C++ project where we're about to run out of flash.
A quick check of the map file give that, in our case, the destructors consume about 10-15% of the available space. Since we're allocating all things that are needed at startup but never delete anything (both a requirement & also impossible due to the lack of a proper memory manager) the thought of getting rid of all destructors in the target build is appealing.
I know that this question is somewhat crazy/desperate but is there a safe way of telling gcc not to emit any code for destructors? If so, can that be made in such a way that a linker error catch for instance mistakes such as creating an object on stack?
View 12 Replies
View Related
Jan 21, 2014
The compiler creates virtual table for the base class and also for the derived class whether we override it or not.
That means each class has separate virtual table. when we get the size of the each class with out any data members... the size of base is -- 4 bytes(64 bit) and the size of derived is -- 1
The size of base class 4 is correct since it creates the virtual pointer internally and its size is member data + virtual pointer, but it in this case I have included any data members so it has given 4 byts.
But why in case of derived is 1 byte, since it the derived class has overridden the virtual function from base, this will also contains the virtual pointer which will be pointing to derived class Vtable, it the size of the class suppose to be 4 instead of 1 byte.
#include<iostream>
class A{
public:
[Code].....
View 1 Replies
View Related
Jan 17, 2013
I was trying to make a program of calculating simple intrest using functions. I don't know whats wrong with the program but it always shows a wrong output.
#include<iostream.h>
#include<conio.h>
float si(int p,int r,int t) {
return ((p*t*r)/100.0);
[Code] ....
View 4 Replies
View Related
Feb 21, 2014
I already wrote a program that will calculate the gross pay for a set of employees.
I want modify the code by adding multiple functions.
I want to create a separate function whenever possible to break up the program.
For example, I would like have a function for obtaining the hours from the user, another function for calculating overtime hours, another for calculating gross pay and another function for producing the output.
#include <stdio.h>
#include <stdlib.h>
#define STD_HOURS 40.0
#define OT hour>STD_HOURS
#define SIZE 5
int main() {
int clockNumber[SIZE] = {98401, 526488, 765349, 34645, 127615}; /* employee ID */
[code]....
View 2 Replies
View Related
Jun 9, 2014
This program in not completed. I am creating a large program in order to calculate a company's weekly payroll. For now I am filling in the separate functions piece by piece before the rest of the program is completed.
Right now I am trying to use separate functions to call other functions. I need to ask the user for the file name and then open the file. I am no longer getting any compiler errors however when I run the program all it displays is "Welcome."
So it's not actually calling the NameTheFile function and the OpenTheFile function. It just says "Welcome" and then closes down. Why is it doing this?
/*Program to determine company's weekly payroll*/
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
void NametheFile() {
ifstream inputFile;
[Code] ....
View 1 Replies
View Related
Jul 24, 2013
This is an assignment which the purpose is to calculate an angle value in form of trigonometric functions. These are the codes that I've wrote so far.
#include <iostream>
#include <cstdlib>
using namespace std;
void menu(double &value) {
system("cls");
cout<<"*****Trigonometry Program*****"<<endl;
[Code] ....
I have completed the codes for the interface part. Before I proceed with the formula for the trigonometric functions, I would like to make sure the program is Error-free, which if there is accidental invalid input from the user, the program would the user to enter another input until it is a valid response.
The only problem I have encountered for this matter was in menu(value)
If I enter an integer, the program will proceed without error. However, If I enter a character, the program will slip into an endless loop which constantly shows this
*****Trigonometry Program*****
Please enter an angle value => Is the angle in Degree or Radian?
Type D if it is in Degree
Type R if it is in Radian
Your response=> 0 //my initial input for value
Do you want to continue?
Type Y to continue
Type any other key to stop
Your response =>
Where is the source of the problem? I'm pretty sure it's the loop, but I don't know what to do.
View 2 Replies
View Related
Sep 14, 2014
I want this programming to call functions choose between a customer type and call the relevent function to calculate the final price but it is not calling the functions.
#include <iostream>
using namespace std;
double amount;
double studendOrPensioner(int&choice, double &origPrice);
double OtherCustomers(int&choice,double& origPrice);
[Code]...
View 1 Replies
View Related
Feb 20, 2013
I have this program I wrote to calculate cost for the production of open top cylinders and how to translate it into user defined functions. Here are the user defined functions I need to use instruct() get_area() comp_area() and print_area_cost() so the program will be in 4 parts.
Code:
#include <stdio.h>
int main()
{double radius,height,cost,single,all;
float surface_area;
int count;
double pi=3.14159265;
printf("Enter the radius of the base in cm^2:
[Code] ......
View 2 Replies
View Related
Dec 27, 2012
class Parent{
public:
virtual int width();
virtual int height();
int area(){return width()*height();};
[Code] ....
View 10 Replies
View Related
Oct 23, 2013
I am trying to create a NFA from a regular expression. I have a grasp on reading in the regular expression and being able to make a stack from it. The part I am struggling on is mapping the characters in the regular expression to an integer indicating the variables order in the expression. I am just not sure how to go about this.
My code so far...
Code:
#include<stdio.h>
#include<stdlib.h>
#include "stack.h"
int main(void)
{
char expression[80];//array to store regular expression
[Code] .....
View 6 Replies
View Related
Jun 14, 2013
i built a programming language called jade that right now can only print. i want to add variables to it however. I am going to use a modified bajarne stroustrop calculator to handle expressions (ie will now include string manipulations and such), but I want to build a var class into the program to make it easier for the program. i want variables to act like python variabes, and arrays to act like python associative arrays. Ive scoured different containers, but they only work if the variable isnt an array in my language, because it will only have one type. the only thing i can come up with is a union and 4 overloaded = operators (for bool, int, double, and string) is there a better way to do this?
View 2 Replies
View Related
Feb 9, 2015
Basically I want to embed the QGIS canvas widget into a custom application. In order to do that, I need to build QGIS from it's source in order to obtain the devel *.lib, *.dll, *.h, etc. files required. To that result, I am trying to build either version 2.6.* or the current nightly build ~2.7 - 2.8 64 bit version. There is very little documentation on the x64 builds. Not to mention that CMake and I are not the best of friends.
My progress so far:
- Successfully built the extremely out of date nightly build readme instructions of version 0.11 x86
- Partial success in creating CMake output to VS2010, but many required headers were not included such as gqsmapcanvas.h, (So even if I got it building I couldn't use the canvas widget in an application)
*Note I updated the external packages to x64 versions, so it is not an architecture mismatch issue.
I have also had issues with QWT looking for QWT Polar header files, but I suspect this is another issue with the missing headers as most of the errors related to files contained in the original source from GIT.
View 1 Replies
View Related
Jan 7, 2012
Code:
1
121
12321
1234321
123454321 EDIT:
the above pyramid looks like a doom.i.e 1-5 will be in center.1-4(L)1-3(L)1-2(L)1(L) similarly 1-4(R) 1-3(R) 1-2(R) 1(R)
I'm partly successful in building the requirement of the program.but cant able to think the logic for the other half. how can i proceed.below is the code written in c#.
Code:
for (int i = 1; i <= 5; i++)
{
//int l = 1;
[Code]....
View 3 Replies
View Related
Jan 23, 2015
I would like to initialize a N-dimensional matrix by specifying the dimension N.
To be clearer :
if N=2 I use to do that :
std::vector<std::vector<double>> myMatrix;
if N=3 :
std::vector<std::vector<std::vector<double>>> myMatrix;
and so on...
What I would like is to give N as an argument of a function which construct a N-dimensional empty matrix. Is that possible ?
View 2 Replies
View Related
Jan 23, 2013
Making/Building 3D Game Engines, Do I need to know anything related to ART or graphics in order to make them ? I mean, I do know that having a know how about vectors is VERY important, But I am no good at art, I suck. I have thought of getting a separate guy to do the art, as I'm more interested in writing code and then implementing it making use of the art that has been made, I'm just worried if I need to or not need to know anything about sketching or art in order to write a 3D Game engine ?
View 8 Replies
View Related
Aug 19, 2014
I am just getting back in to C++ after 10 years not doing any, contributing to an open source project. I'm adding in some functionality and am hitting a road block.
I need to send a multicast packet out on the network that is structured in a certain way. I have the definition, and know what data is going in each byte. I can successfully send a message using multicast, I now just need to send the right message.
I have used a char array to hold the message, as each char represents 1 byte, and I can transmit the array.
I am having trouble putting all of the data in the right place though. If my source data is a string, then I seem to be able to convert it, but if it is a short or int, then I keep getting errors when compiling. Similarly, two of the lines, (version and type) i initially tried using char arrays with a length of one.
Should I be using memcpy or a different function, or even be doing this in a totally different way altogether? This is the code that I am using, along with the packet structure:
//Construct a Zone Query packet
// 4 bytes - Signature "Ohz " = 0x6f, 0x68, 0x7a, 0x20
// 1 bytes - Version = 1
// 1 bytes - Type (0 = Zone Query, 1 = Zone Uri)
// 2 bytes - Entire message length = 12 + zone length
// 4 bytes - Length in bytes of the zone ID
// n bytes - Zone ID to query
[Code] ....
The errors that I get are:
error: invalid conversion from ‘short int’ to ‘const void*’ [-fpermissive]
memcpy(buffer + 6, packetLength, sizeof(packetLength));
^
[Code] ....
View 9 Replies
View Related
Jun 1, 2013
Let assume that there is an array of integer numbers in the range from 1 to N that are located in the ascending order. For example
#include <iostream>
#include <numeric>
#include <iterator>
int main() {
const size_t N = 20;
[Code] .....
How can it be converted using some one standard algorithm such a way that the resulted sequence would look like
1 3 5 7 9 11 13 15 17 19 20 18 16 14 12 10 8 6 4 2
View 19 Replies
View Related
