All About Interview Of Devloper

  How to delete array of objects in C++? Proof by C++ code for proper deletion Answer includes how to delete array of objects in C++ created dynamically with C++ code example with proof. In other words, delete array of pointers to objects in c++. Interview Question: Write C++ code to create an array of objects using new keyword and delete these objects. Also, proof that all the objects are deleted properly. Answer: We know that when we create an object of a class dynamically from heap memory using new keyword, then we must delete it explicitly to avoid memory leaks in C++ programs after we are done with its operations. Let’s take below class Pen as an example. class Pen { public: Pen() { cout << "Constructor..." <<endl; } ~Pen() { cout << "Destructor...!" <<endl; } void write(){ cout << "Writing...!" <<endl; } }; Below is an example, how we create an object ...

  What is virtual destructor in C++? Why do we need virtual destructor? Answer includes what is virtual destructor in C++ with example and use of it or why do we need virtual destructor in C++ object oriented programming. Note that in an interview, if it asked about virtual destructors then don’t forget to answer when to use virtual destructor in C++ class. Also, note that there is no  concept of virtual constructor in C++ programming. Answer:  Virtual destructors maintains the hierarchy of calling destructors from derived to base class. A class must have a virtual destructor if we hit below criteria. Derived class object using a pointer to base class and deleting base class pointer. For example Base * p = new Derived (); // up casting Delete P; If we don’t make base class destructor virtual, it will not call derived class destructor on above mentioned criteria. For example class Base{ public: ~Base(){cout<<"Base class destructor..."<<"\n";} //not virt...

  A good interview question based on a C++ polymorphism in oops C++ Technical Interview Question on polymorphism in oops Write a complete class stating function overriding feature in C++ Show the function call in main program. Explain the concept of function overriding. Take example of drawing multiple shapes e.g. circle and rectangle etc. Interviewer Intent: You know the concept and syntax of function overriding in C++ you can write class and program. If you follow best coding practice and the things you care when write the code. NOTE:  As per question criteria, we will write code using interface, but, to describe the concept a basic example will be covered first. Answer: Function overriding concept is run time polymorphism in oops, in which functions get resolved on run time using VTABLE (Virtual table) by compiler. If we have definition /declaration of a function in base class and want to have a definition of same function name in derive class and want to call derived funct...

  Question 1. Define Image? Answer : An Image may be defined as a two dimensional function f (x,y) where x & y are spatial (plane) coordinates, and the amplitude of f at any pair of coordinates (x,y) is called intensity or gray level of the image at that point. When x,y and the amplitude values of f are all finite, discrete quantities we call the image as Digital Image. Question 2. Define Image Sampling? Answer : Digitization of spatial coordinates (x,y) is called Image Sampling. To be suitable for computer processing, an image function f(x,y) must be digitized both spatially and in magnitude. Question 3. Define Quantization ? Answer : Digitizing the amplitude values is called Quantization. Quality of digital image is determined to a large degree by the number of samples and discrete gray levels used in sampling and quantization. Question 4. What Is Dynamic Range? Answer : The range of values spanned by the gray scale is called dynamic range of an image. Image will have high co...