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What is the use of virtual destructor?
mehulgala177
- Sep 22nd, 2011
You should always keep your destructors virtual when u r dealing with Inheritance. Try this Code :
Code- #include <iostream>
- #include <tchar.h>
- " Destroying Parent
- "" Destroying Child
- "Also try the same code without using virtual keyword before ~Parent() u will see the difference... :)
rimsha
- Jul 27th, 2011
Virtual destructor is used to delete the dynamically allocated memory via a base class ptr.
C Double dimensional arrays
How can double dimensional arrays be dynamically initialized in C ?
Ajay Kanse
- Dec 23rd, 2008
There are multiple ways to do this :1. int **arr = (int**) malloc(nrows * sizeof(int*)); for (i=0 ; i<nrows ; i++) { arr[i]=(...
SomGollakota
- Jun 13th, 2007
If the question is "How to initialize memory that is dynamically allocated for a 2D array", there are a couple different ways.1. Use memset. memset sets a chunk of memory to a given value. U...
1.why constructor can't be virtual?2.what's the difference between destuctor and virtual destructor?
Jos Collin
- Oct 4th, 2011
That's not correct. The VTable will be created completely during compile time itself. The reason why constructor can't be virtual is that the virtual mechanism will work only on completely constructed...
anabarai
- Jul 5th, 2011
There is nothing like Virtual Constructor. The Constructor can’t be virtual as the constructor is a code which is responsible for creating an instance of a class and it can’t be delegated to any other object by virtual keyword means.
Reverse A Linked List
What is the most efficient way to reverse a linklist?
shantanu_hbd
- Apr 25th, 2009
#include<iostream.h>#include<stdio.h>#include<conio.h>class Node{ public: int data; Node(int data); Node *next; void display();};Node::Node(int data){&nb...
What is difference between inline function and ordinary function?
sachin_mundhra
- Jan 28th, 2010
Inline function should be small in terms of line of code. Complier will replace the code whenever inline function gets called.
wow_suraj
- May 2nd, 2008
In case of ordinary function, when calling the function the scope jumps to the function and after return jumps back to the function call statement resulting in some extra execution time. While in case...
What is the difference between structures and classes in C++?
There is only one difference ,in classes the members are private by default whereas it is not so in structures.
sripudi
- Jan 5th, 2009
There are a lot of differences between Structure & Class in C.But in C++ the only difference is the members structure are by default public where as class members are by default private.Using C++ structure?we can do the OOPS concepts like inheritance
berezleon
- Dec 1st, 2007
Amid, you are talking about "C" structure that knows nothing about classes etc. The only difference between C++ class and struct is default access specifier (private and public respectively)
What is defference between constructor and destructor
srabani_mazumder
- Aug 30th, 2010
Like constructor, the destructor is a member function whose name is the same as the class name but is preceded by a tilde. For example the destructor of a class integer can be define as :- ...
ankitagujrati28
- Jul 21st, 2010
Constructor is the member of a class which is called implicitly when the instance of class is created. It allocates the memory to data.Same as destrutor is also a member of a class. It is called implicitly at the end of execution of class. It deallocates the memory.
Count Number of characters using Pointers
Write a program to count the number of characters in a string using pointers.
madhuti
- Sep 29th, 2009
Int main(void) { char* str = "Hellolklklk"; int i=0; for(i=0; *str; i++, str++); printf("count= %dn", i);return 0;}
paindriven
- Jun 12th, 2009
unsigned int charCounter(char const* str){ unsigned int counter = 0; char const* data = str; while (data != NULL && *data != '') { data++; counter++; } return counter;}
Why Pointers are not used in C Language. What are the main differences between C and C++
How to create an object such that it should not call constructor by default.
Indrajit
- Jul 22nd, 2007
Virsa's questions, why constuctors cannot be private and the difference between... are not related to the original question at all, and I simply don't understand why people even take the pain of answe...
dasam
- Mar 29th, 2007
Adam is absolutely correct. It is not illegal to make the constructor as private. We generally do this while creating the singleton class patterns.
Difference between realloc() and free()?
The free subroutine frees a block of memory previously allocated by the malloc subroutine. Undefined results occur if the Pointer parameter is not a valid pointer. If the Pointer parameter is a null value, no action will occur. The realloc subroutine changes the size of the block of memory pointed to by the Pointer parameter to the number of bytes specified by the Size parameter and returns a new...
SomGollakota
- Jun 13th, 2007
free() - releases the memory of the pointer passed as parameter, to the OS/application consumption. Using the pointer after free() will result in undefinded resultsrealloc() - used to resize the memor...
Roopesh Majeti
- May 27th, 2007
Mitra,as you mentioned that realloc will delete the existing memory and allocate the new memory . I tried it on solaris and following is found :1. If the new size allocated is less than the existing m...
What do you mean by inline function?
The idea behind inline functions is to insert the code of a called function at the point where the function is called. If done carefully, this can improve the application's performance in exchange for increased compile time and possibly (but not always) an increase in the size of the generated binary executables.
Sampada Wadkar
- Apr 9th, 2012
An Inline function is a function that is expanded in line when it is invoked. That is compiler replaces the function call with the corresponding function code.. :)
Code- CO06203
MCBod
- Mar 31st, 2010
An inline function is a function where a copy of the logic is embedded in the application at each the point where it is called by the compiler. This basically allows a reduced overhead in function dereferencing
What is the difference between a pointer and a reference?
sachin_mundhra
- Jan 28th, 2010
Pointer can be NULL but reference cannot be NULL.For example, If you write int &a; // This will give compile error, because reference cannot be NULL.
pammi_11
- May 10th, 2008
Pointer holds the address of a variable.reference holds the address of duplicate of that variable.
What is the need /use of function overloading
Hint FO is mechanism in which two functions r having same name with diff no. of arguments.
What is the difference between static global variable and static local variable?
yzesong
- Jul 31st, 2009
They have almost same lifetime(local is shorter), but different access scope.
burraganesh
- Dec 7th, 2008
For both these the default initial value is 0A static global variable can only be accessed in the file it exists, we cannot use it in other files, even after mentioning it as externIn static local var...
How will you detect if there is memory leak in your C++ program?
vijay.badola
- Oct 4th, 2009
In LINUX environment one can use VALGRIND and MPATROL free tools to find out possible memory leaks in programs.
santhosh.kanchanapally
- Feb 18th, 2009
By overloading the new and delete operators, we can find the memory leaks as shown in following program ,#include "stdafx.h"#include <iostream>#include <string>using namespace st...
Inheritance
What is inheritance? why we use it? plzz can anybody explain me with one example and where we use that concept?
navneet.navu
- Apr 19th, 2010
It is an object oriented feature which provides the reusablity of code. All the properties defined in the parent class can be used by its child classes without writing the code again.
Samuel Rengarajan
- Dec 11th, 2009
All Common features are come to parent class. So we can extend this class to child classes. Child classes contais some special features.Useage of inheritance : it reduce the code. If we use inheritance, we avoid redundent code.
Inline Function Advantages
What are the advantages of inline functions over macros?
ashwin2090
- Aug 28th, 2009
Inline function very much confused to use it or not.Well I want to just tell you that it has large number of disadvantages than advantages Inline function works faster than normal function. They are ...
AnisHasan
- Jul 16th, 2009
Beside the adventages which are mentioned there are some more advantages of Inline Functions over Macros1> Macro call is resolve at the compile time and compiler replce Identifier with charecter se...
Placement New Syntax
How can a C++ developer use the placement new syntax to make new allocate an object of class SomeClass at a particular memory address stored in a pointer type variable named pmem?A. new SomeClass(pmem);B. new(pmem) SomeClass;C. new SomeClass pmem;D. new pmem SomeClass;E. new (pmem, SomeClass);
ajrobb
- Sep 22nd, 2010
BWhere you use placement new, it is important to explicitly call the destructor for the object before re-using the memory.Fred * fred = new(pmem) Fred();...fred->~Fred();fred = 0;George * george(pmem) George();
akash_saxena
- Dec 22nd, 2009
It is B. new(pmem) SomeClass;pmem points to the memory which shall be used.
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