Sandy is of class Person, who converts to Muslim and takes on a new name Fatima, and has all the attributes of Sandy, with new Muslim attributes (e.g. religion == Islam, etc..). At this point, Sandy can be deleted, and Fatima, now of class Muslim will play Sandy's role henceforth. The problem is that due to her new address, all the people who knew Sandy does not know Fatima. Manually changing Sandy's address to Fatima's address for all those people who knew Sandy is clearly not an acceptable method. I looked through all the design patterns and cannot find one to solve this problem. how to improve the design? Here's my simplified code showing the problem:
#include <iostream>
#include <string>
#include <typeinfo>
class Person {
std::string name;
Person* bestFriend;
[Code]...
Output:
sandy = 0x32658, 6Person
Mary's best friend is Sandy.
fatima = 0x23fec0, 6Muslim
Mary's best friend is Sandy.
Of course, we want to have: Mary's best friend is Fatima,. with mary->getBestFriend()->getReligion() == Islam, etc... How to redesign the whole thing so that this is automated (assume there are thousands of people who know her)?
#include <iostream> #include "curve1.h" #include "curve2.h" using namespace std; int main() { Curve1 curve1Obj; Curve2 curve2Obj;
[Code]...
Base class Score has two derived classes Curve1 and Curve2. There are two curve() functions, one is in Curve1 and other in Curve2 classes. getSize() returns the value of iSize.
My base class header score.h looks like this:
#ifndef SCORE_H #define SCORE_H class Score { private: int *ipScore; float fAverage; int iSize;
[Code]...
You can see that I have used curve1Obj to enter scores, calculate average and output. So if I call getSize() function with cuve1Obj, it gives the right size that I took from user in enterScores() function. Also the result is same if I call getSize() in score.cpp definition file in any of the functions (obviously). .....
The problem is when I call curve() function of Curve2 class in main (line 23) with the object curve2Obj, it creates a new set of ipScore, fAverage and iSize (i think?) with garbage values. So when I call getSize() in curve() definition in curve2.cpp, it outputs the garbage. .....
How can I cause it to return the old values that are set in curve1.cpp?
Here is my curve2.cpp
#include <iostream> #include "curve2.h" using namespace std; void Curve2::curve() { cout << "getSize() returns: " << getSize() << endl; // out comes the garbage }
Can I use a function to simply put values from old to new variables? If yes then how?
I am writing a program which is using SDL library. I have two different classes which one of them is Timer Class and the other is EventHandling Class.
I need to use some member functions and variables of Timer in some Eventhandling Class member functions, Although I want to define an object of Timer in int main {} and relate it to its member function that has been used in Eventhandling member function in order that it becomes easier to handle it, I mean that I want to have for example two objects of timer and two objects of Eventhandling class for two different users.
I do not know how to relate an object of a class from int main{} to its member function which is being used in another class member function.
Creating array in main and then calling a sorting function from sorting class.
In main:
const size_t SIZE = 100; int *array = new int [SIZE]; //fill array with ints, not shown here quickSort(array, SIZE); //calling the sorting function in the sorting class
In the sorting class, quickSort is declared as such:
void quickSort(int arr[], int num);
Everything works great.
Version 2 (issues)
Instead of creating the array in main, I have set up a class for the array, MyArrayClass, where I create an object containing the array of ints. So far so good. The issues come when I write a member function to call quickSort. Even though my MyArrayClass object contains an array of ints, the code calling for quickSort() won't compile as the data type isn't ints but MyArrayClass (which in turn holds ints though). The compiler (using VS 2013 btw) complains that quickSort can’t convert the first argument from 'const MyArrayClass' to 'int[]'.
How do I cast my class object array of ints as an int[] in order to be able to call the quickSort function? Or should I solve this issue in some other way? I tried altering the sorting function to accept the object as it is, but that only created an avalanche of new errors, so thinking that converting/casting the object array --> int[] might be easier...
I have a class MySeqBuildBlockModule that I am inheriting from: public SeqBuildBlock. Other than constructor and destructor, this class MySeqBuildBlockModule has a method: prep.
class MySeqBuildBlockModule: public SeqBuildBlock { friend class SeqBuildBlockIRns; public: MySeqBuildBlockModule (SBBList* pSBBList0, long TI1_In, long TI2_In)// more arguements in this constructor of derived class : SeqBuildBlock (pSBBList0)
[code]....
I would have like to intiantiate an object "myIRns_3" of a class defined in third party library
SeqBuildBlockIRns myIRns_3(pSBBList2);
and would like to access it from the prep function as:
I tried to instantiate following in either private section or in constructor; but w/o any success:
SeqBuildBlockIRns myIRns_3(pSBBList2);
ERRORS encountered:
When I tried to do it inside the constructor, I get the following errors:
MySBBModule.h(113) : error C2065: 'myIRns_3' : undeclared identifier MySBBModule.h(113) : error C2228: left of '.getEnergyPerRequest' must have class/struct/union type MySBBModule.h(116) : error C2065: 'pSBBList' : undeclared identifier MySBBModule.h(116) : error C2227: left of '->prepSBBAll' must point to class/struct/union
When I tried to do it in private section, I get the following errors:
MySBBModule.h(106) : error C2061: syntax error : identifier 'pSBBList2' MySBBModule.h(113) : error C2228: left of '.getEnergyPerRequest' must have class/struct/union type MySBBModule.h(116) : error C2065: 'pSBBList' : undeclared identifier MySBBModule.h(116) : error C2227: left of '->prepSBBAll' must point to class/struct/union
I am trying to write a Fraction class and getting the following warning when compiling my code :
Fraction.cpp: In constructor 'Fraction::Fraction(double)': Fraction.cpp:8: warning :converting to 'int' from 'double'
My Fraction.cpp class looks like :
#include "Fraction.h" Fraction::Fraction(int n, int d):num(n),den(d) { cout << This is double param constructor <<endl; } Fraction::Fraction(double d):num(d),den(0)
I'm writing a class to store a tree I have a small issue.
I have a class which stores a node of the tree, something like this:
template<class T> class node { private: (stuff regarding parent node and child nodes); T __data; public: // more stuff (constructors and utility functions) here };
And I want to I want to be able to do the conversion T(node<T>) implicitly. For example, I want to be able to do this:
node<int> myNode; myNode=5; myNode+=10; myNode*=9; int x=int(myNode/4); cout << x+myNode;
And this:
class myClass { int x; int y; void print () {cout << x << ' ' << y << endl;}
Information: I'm using Code::Blocks v12.11. (I'm using C++/SDL2, but I think that's of no relevance)
Problem: I create a class named "CSprite" in a "Sprite.hpp"-file. I create a "Sprite.cpp"-file, which includes the "Sprite.hpp"-file. I define the methods of the class "CSprite" in the "Sprite.cpp"-file.
When I try to create an object of "CSprite" in the class named "CPlayer" in the file "Player.hpp" I get an error message. (<-- Looks complicated I know, the code example will be more usefull than this)
Error in the build messages: C:UsersLinoDocuments1 Data LinoFreizeit1 ProgrammierenC++ & SDL2The Running ManCPlayer.h|30|error: 'CSprite' does not name a type| ||=== Build finished: 1 errors, 0 warnings (0 minutes, 1 seconds) ===|
Code Example:
Sprite.hpp #ifndef _SPRITE_HPP_ #define _SPRITE_HPP_ class CSprite {
[Code] .....
What did I miss? Did I include the wrong file? Or did I Forget to include the file? Why do I get the error message?
I also tried it with a pointer declaration and the "->" Operator but I got the same error message. I know I could just write a new function to load the texture in my "CPlayer"-class but this would not really answer my question.
I fully understand that a variable of one simple data type cannot be assigned to another of a different data type in an assignment statement, except when type-conversion(i.e. casting) is employed. For structured data types (like classes), I know that the assignment operator can be overloaded; but this only addresses objects of the same type.
My problem is that I have read data from an input file into an object of one class, but I want to transfer the contents into an object of a different class in an assignment statement. Can this be realized given that the two operands of the assignment operator (=), in this case, would be of two different types?
I have two classes one called Date and the other is University , Date class has two overloaded operators , ostream and istream to take in the data and print them out :
The University class has an object of type Date called establishDate and I must use this to print out the date along with the University name and location, here's University class :
University.h
class University { public: University (); // constructor friend ostream & operator<<(ostream & out, University & x); // print the university data friend istream & operator>>(istream & in, University & x); // to read university data
I am having trouble working with third party dll's, libs and header files. I am trying to call a function.here is the function that is suppose to be called.
Name IN/OUT Description m_environment IN Optional. Possible values are SANDBOX (default) and LIVE. m_strConsumerKey IN OAuth consumer key provided by E*TRADE m_strConsumerSecret IN OAuth consumer secret provided by E*TRADE m_strToken OUT Returned by the function if successful m_strTokenSecret OUT Returned by the function if successful m_strCallback IN Optional; default value is "oob"
#include <iostream> #include <vector> #include <string> #include <map> using namespace std; struct bop { string realname; //real name
[Code] ....
Okay, so first thing's first. The program will not compile due to lines 39-45. If I were to change those pointers into regular objects, it will not change the values of my class object. So what is the right way to do this?
I want the user to be able to input the # of employers/programmers into the system. But I cannot do that with an array of classes because when declaring an array; the array size must be constant.
make a class that you can make only one Object of it.
For example if you have Class A. Let's say you create one object A* a=new A();
Now the next time you, try to create another object. For example:
A* b=new A(); What will happen is that b will get the same object (or reference) as a. In other words hey'll be pointing towards the same place. So basically you'll only have one object of it created. I tried doing it but I couldn't quite make it.
Here is what I tried: (but couldn't complete the exercise)
class God { public: static int num; static God* god;
