Search DaniWeb - destructors

destructors in ruby 15 Years Ago by kinger29 Is there any such thing as destructors in ruby. I am trying to figure out how to destroy an object. C++ newbie: 2D dynamic array--how do destructors work? 13 Years Ago by Annettest … appreciate some help with understanding how to free memory/use destructors. I have created a 2D dynamic array template class. I… guidance. 1) I may not understand correctly how to use destructors (more below). 2) I am overloading () to use (i,j… say that I may not know correctly how to use destructors, I mean that I'm not sure HOW to call… help with inheriting constructors and destructors 13 Years Ago by jimmymack …] I don't understand why it doesn't show the destructors being called in the output? In the book I'm… using for the above code it shows the constructors, destructors and methods being called in the output. But mine isn… number of constructor and destructors called 14 Years Ago by gauravmishra … program 4 constructors are called (including copy constructors) and 4 destructors as expected(as expected). but when i uncomment the assingment… operator 5 constructors are called and 5 destructors are called but i expected 6 constructors to be called… Re: help with inheriting constructors and destructors 13 Years Ago by mike_2000_17 … in, it reaches the end of main()) and then the destructors are called. I guess under some operating systems or under… Thread Problem Error: constructors, destructors and class operators 10 Years Ago by fernandofranca … dont know why I´m getting the error Error: constructors, destructors and class operators must be methods I have my Unit1… got the error "portaserial.pas(92,25) Error: constructors, destructors and class operators must be methods" If everything is… Re: Need 4 destructors !! 17 Years Ago by John A >We have implicit destructors defined , when their actual definition is absent . No, since you … Leak ??? Yep. To fix the problem, look into [search]virtual destructors[/search]. Constrcutors and Destructors 17 Years Ago by vicky_dev … concatenate two strings, but I am having trouble with constructors/destructors.:rolleyes: Please explain the exact sequence of calls and the… Need 4 destructors !! 17 Years Ago by gpta_varun …() { test * pctest = new test_derv; delete pctest; } [/code] We have implicit destructors defined , when their actual definition is absent . Does that mean… Contructors and destructors problem 16 Years Ago by rag84dec … the below code i could see 2 constructors and 3 destructors being called....i want to know why....can anyone help… Constructors and Destructors 13 Years Ago by Nathaniel10 …. It is supposed to have different types of constructors and destructors, variables created and variables destroyed. It prints out whenever a… Where are destructors used in c language? 12 Years Ago by Rajbeer Where are destructors used in c language? Re: Where are destructors used in c language? 12 Years Ago by lxXTaCoXxl … back the memory that was borrowed to store the item. Destructors are also called when the application exits. Any destructor implicitly… Re: Where are destructors used in c language? 12 Years Ago by lxXTaCoXxl … answered the thread perfectly. We all know there are no destructors in C because it's not object oriented; so I… Delete in destructors? 12 Years Ago by triumphost When do I really need to use Delete in Destructors? if I do Point P = new Point(); I've been … Re: Delete in destructors? 12 Years Ago by mike_2000_17 …;> When do I really need to use Delete in Destructors? When your class is responsible for allocating the memory that… virtual consructors and destructors 9 Years Ago by nitin1 Why can we virtual destructors but can't have virtual constructors? I have searched like anything. I got confused a lot after reading few articles on web. Please explain with some good example. Thanks in advance. Re: destructors in ruby 15 Years Ago by destin Objects are destroyed for you by the garbage collector. Re: 3 C++ questions - destructors, derived class, abstract class 15 Years Ago by MrSpigot … contsructor? [/QUOTE] You're clearly realising that the Constructors and Destructors are not your average method. Good stuff. [B]1.1… a base class, be inherited by a derived class?[/B] Destructors and constructors don't behave as other methods. Even if… Re: Correct implementation of destructors in base and derived classes 10 Years Ago by tanatos.daniel … have specification to create them, but to correctly implement the destructors. I guess this was the catch(if i do or… Re: C++ newbie: 2D dynamic array--how do destructors work? 13 Years Ago by StuXYZ I would like to see all of this class, well in particular the copy and assignment operator, as well as the default constructor. The correct constructor should have: [code=c++] arrayInstance = new T*[rows]; for (int i = 0; i < rows; i++) arrayInstance[i] = new T[cols]; [/code] the destructor should have [code=c++] for (int i = 0; i < rows… Re: C++ newbie: 2D dynamic array--how do destructors work? 13 Years Ago by Annettest Thanks a lot for your help, StuXYZ. Sorry, I made a typo. My arrayInstance is T** array. I don't have a default constructor because I thought it would be sufficient to have a constructor that takes arguments (i,j) that specify the matrix size. Am I wrong? Regarding your end comment (b), what do you mean by, "as long as the memory… Re: C++ newbie: 2D dynamic array--how do destructors work? 13 Years Ago by StuXYZ The mistake is almost certainly with the copy and assignment operators. You will get both, auto written by the compiler if you don't provide them. In this class both will be 100% wrong, as they do a shallow copy. So either, prove that they don't get called: E.g adding [code=c++] private: Array2d(const Array2d<T>&); Array2d<T>&… Re: C++ newbie: 2D dynamic array--how do destructors work? 13 Years Ago by Annettest Thank you very much StuXYZ. I was not aware of this. I must stop for the day, but I will write a copy/assignment operator tomorrow. Re: C++ newbie: 2D dynamic array--how do destructors work? 13 Years Ago by Annettest Hi StuXYZ: I tried implementing copy/assignment operators by adding the code below to my header and .cpp files, but I'm still getting Xcode crashes. Would you mind taking a look at my code and commenting about any problems? I may have made some silly mistakes because I'm not sure I understand copy/assignment operators as well as I should.… Re: C++ newbie: 2D dynamic array--how do destructors work? 13 Years Ago by StuXYZ The copy constructor looks ok, with the exception that you must put a guard in for rows==0 and cols==0, but the assignment operator is a mess. The problem is is that if you reassign memory you haven't deleted the old memory. In particular you call the delete operator directly from the class, this is almost always a serious error. This is much … Re: C++ newbie: 2D dynamic array--how do destructors work? 13 Years Ago by Annettest Thanks a lot for your help, StuXYZ. Unfortunately, Xcode is still crashing though! Although the error is now "uncaught exception." If you do have any further suggestions, I would love to hear them if you have time. Thanks again! Re: C++ newbie: 2D dynamic array--how do destructors work? 13 Years Ago by StuXYZ It seems like it is actually some other part of your code now. You could run your code in the debugger. If you can write a simple test case for array2d, then post the whole code here. [At the moment, we have nothing that we can actually run.] You can also put a simple [icode]try { // your code here } catch (std::exception& A) { std::cout<&… Re: C++ newbie: 2D dynamic array--how do destructors work? 13 Years Ago by Annettest Thanks a lot Stu for your help. I'll try the test case! Re: help with inheriting constructors and destructors 13 Years Ago by Chilton Did you press enter after you ran your code?