C++ :: How To Copy From A Dynamic Array Initialized In A Class
Apr 3, 2013
How do I copy from a dynamic array initialized in a class but with a different memory address. For example if my array is a dynamic array initialized in a class...
Code:
const int CAPACITY=5;
class Array{
public:
Array();//constructor
[Code] .....
How would i copy this array to a another array but have a different memory address so when i deallocate array a my copy array also isn't deallocated.
I am trying to figure out copy constructors for a dynamic array and I am definitely missing something. If I go into the copy constructor routine during debug, the values appear to be correct but they don't percolate up to the newly created object. I'll post a portion of the code below:
Code:
// include header files for the classes that are being used #include "stdafx.h" //
NOTE: THis reference must be added to all cpp files in Visual Studio Express 2013
#include <iostream> #include <string> #include <cstdlib> #include <map> using namespace std; const int ARRAY_SIZE_DEFAULT = 32; class vectorOfInt { public:
[code]....
The size of c is 0. Values of a were not copied to c, although they appear to do so within the copy constructor routine.
I have a problem in dealing with dynamic arrays. I have initialized the objects and now i want to print them.
Code: // main char* namesList[] = {"Brad Shaw","Aimen Adams","Sal Dimitry","Cristi Anreaz","Poala James"}; int idList[]={232,444,135,52,134}; Team t1( namesList,idList,5,"waqas"); t1.Print_team(); My class Team looks something like this:
[Code] ....
The print function does not work. I have to implement the print function without taking any parameters.. How should i do that ?
I'm writing a class that has two constructors. However, I can't get them to work quite right. One constructor has a parameter of an int (with a default value of 0) and the other has a parameter of a C-style string.
First of all, are these function prototypes correct for the constructors?
MyInt(int n = 0);// first constructor, int param, default value 0 MyInt(const char * c);// second constructor, c-style string param
Both constructors work fine in some cases but don't work in all cases. Here are some potential calls to these functions that are supposed to work:
// These two work fine MyInt x(12345), y("9876543210123456789"), // The array assignment doesn't work when the value is negative // I'm not allowing negative numbers, but I want to create the object and assign the array to 0 r1(-1000),
[Code] .....
Here's the private data from the class (from the header file):
private: int currentSize, maxSize; char* digits;// Pointer to an array of digits
// Increase the size of digits array by 5 void Grow ();
I attempted to create a dynamic array class for use in my engine (due to problems regarding a dll-interface with the standard library), so I tried at making a standard-compatible allocator template class first. After I "finished" that, I went on to work on the dynamic array class itself.So I finish the dynamic array class, and test it with the standard allocator. It works perfectly, but when I test it with my custom allocator class, it fails terribly.
To make sure it wasn't my DynamicArray class that was causing issues, I tried using the custom allocator on the std::vector class template, and it didn't work either. IMy DynamicArray class code:
// Represents a dynamic array, similar to the standard library's "vector" class. template<typename T, typename A> class DynamicArray { public: DynamicArray() : data(nullptr), elements(0), capacity(0)
[code].....
The "Request" and "Free" functions are my engine's equivalent of malloc and free (or new and delete). I allocate a large buffer (16 mb), and through those functions I distribute the memory to where it's needed.
I have a class called Book and I am trying to create a dynamic pointer based array of the class. When I try to run the program I keep getting the error: pointer being freed was not allocated at the line of code that says "delete [] A;". I am using Xcode to run the program.
Book *changeArraySize(Book *A, int &size, double factor) { int i; int newsize = size*factor; Book *A2 = new Book[newsize];
I want to be honest, this is FOR homework, but is NOT homework. I have created this example to work from in order to understand qsort further because the next assignment requires it's use.
Our teacher gave us this small piece of example code and I am trying to expand on it to serve my purpose. [C] Sorting - Pastebin.com
The code gives me no errors, but does not sort the array. Need to clarify the use of qsort in this instance.
I am imagining that the reason it's not sorting properly ( or at all ) is because of my comparison function. That is really just an assumption. Or perhaps I just don't understand the pointer array i'm using.
Code: #include <stdio.h> #include <stdlib.h> #include <string.h> int main(int argc, char *argv[]) { int i; int arr[3];
[Code] ....
Notice we didn't set a value for second index but it returns 0. Should I assume that when declaring an array with n values, those values will be initialized to 0 automatically or should I still initialize the array with all 0s doing something like this:
I'm writing a program in which I have to use a matrix to represent a file in code. because it's a file, the size of the matrix is undefined, and therefore the matrix has to be dynamic. I found out that my compiler doesn't like dynamic multidimensional arrays, so I was thinking of this matrix as a dynamic (monodimensional) array of other dynamic (monodimensional) arrays. My program (and thus this example) uses unsigned chars.
Im supposed to create an array of eight Circle objects initialized with the radii which is in the program. Also I must use bubble sort to arrange the objects is ascending order.
ERRORS: 'initializing' : cannot convert from 'double' to 'Circle' 'setRadius' : is not a member of 'Circle' see declaration of 'Circle' 'findArea' : is not a member of 'Circle' see declaration of 'Circle
#include "stdafx.h" #include <iostream> #include <iomanip> using namespace std; class Circle {
Is there a way to copy a derived class object thru a pointer to base?
For example:
class Base { public: Base( int x ) : x( x ) {} private: int x; }; class Derived1 : public Base { public: Derived( int z, float f ) : Base( z ), f( f ) {} private: float f;}; class Derived2 : public Base { public: Derived( int z, string f ) : Base( z ), f( f ) {}
[Code] ....
The question is whether *B[0] would be a Derived1 object and *B[1] a Derived2 object?If not, how could I copy a derived class thru a pointer to the base class?
class Base { char * ptr; public: Base(){} Base(char * str)
[code].....
Obj1 is a derived class object where base class char pointer is initialized with "singh" and derived class char pointer is initilized with "sunil". I want to create Obj2 out of Obj1. Separate memory should be created for Obj2 char pointer (base part and derived part as well) and that should be initialized with the strings contained in Obj1.
Here the problem is: Derived class part can be initialized with copy constructor. How to initialize the base class char poniter of Obj2 with the base class part of Obj1. char pointers in both the classes are private.
I tried using initializer list but could not succeed.
I just wondering if there's a way in C++ to get classes dynamically which have the same base class? I mean, instead of creating switch statement to create multiple classes, I would like to use a single line to create any of these classes.
//Instead of: switch(class_type) { case type_1: SubClass_1 obj = new SubClass_1();
#include <iostream> using namespace std; class Foo { public: Foo( int n );// Constructor ~Foo();// Destructor int *ptr; int N;
[Code] ....
I'm using Visual C++ 2008 version. The problem arises at the end, after the sentence 'system("pause")' is reached, which makes me think that the problem happens when calling the destructor. The destructor is called twice, the first time it's called is in the function print. The problem seems to be that the destructor can only be called once.
I know I can avoid this situation by defining the function print like this:
void print ( const Foo &f ) ...
but I would like to know if there is some way I can do this keeping the definition that I've provided.
I have written this code, and at first glance it does what I want, however I am worried that
a) I am overwriting the array that is apssed from chord.getPattern() b) Im getting a memory leak that I want to get rid of, and c) is there generally a /what is the neater way to do it:
Code: uint8_t* ChordBuilder::invert(uint8_t count, Chord chord) { temp = chord.getPattern(); chord.invert(true); //TODO count is how many times to invert. Moves root aswell however
for (uint8_t i = 0; i < count; i++){
[Code] ....
temp is a member variable of ChordBuilder - and is expressed as: Code: uint8_t* temp; I dont want the pattern that chord stores, and passes with getPattern() to change - I fear it is at the moment?
I would rather not use the "new" but I cant think how to get rid of it, however Im not sure where I would need to put the "delete"?
