Never Change the Default Parameters of Virtual Methods

It’s not a good idea to change the default parameters of virtual methods because the default parameters are bound at compile time (static binding), whereas virtual methods themselves get bound only at run time (late binding). Here’s an example:

class Base{  public:    virtual void foo(int i=0){ printf("%d",i); }}class Derived: public Base{  public:    virtual void foo(int i=10){ printf("%d",i);}}main(){  Base *pBase = new Derived();  pBase->foo();}

The expected output, based on the rules of virtual methods would be 10, because the Base pointer is pointing to the Derived object. However, because the default parameters are bound at compile time, they are bound assuming that pBase is a pointer to Base?and not to the Derived object, as is the case. Hence, the output is 0.

Share the Post:
Share on facebook
Share on twitter
Share on linkedin

Overview

The Latest

microsoft careers

Top Careers at Microsoft

Microsoft has gained its position as one of the top companies in the world, and Microsoft careers are flourishing. This multinational company is efficiently developing popular software and computers with other consumer electronics. It is a dream come true for so many people to acquire a high paid, high-prestige job

your company's audio

4 Areas of Your Company Where Your Audio Really Matters

Your company probably relies on audio more than you realize. Whether you’re creating a spoken text message to a colleague or giving a speech, you want your audio to shine. Otherwise, you could cause avoidable friction points and potentially hurt your brand reputation. For example, let’s say you create a

chrome os developer mode

How to Turn on Chrome OS Developer Mode

Google’s Chrome OS is a popular operating system that is widely used on Chromebooks and other devices. While it is designed to be simple and user-friendly, there are times when users may want to access additional features and functionality. One way to do this is by turning on Chrome OS