[2 days left] What’s wrong with your cloud strategy? Learn why multicloud solutions matter with Nimble Storage.Register Now

x
?
Solved

Draw the memory layout of a C++ class with two virtual functions

Posted on 2006-07-11
3
Medium Priority
?
681 Views
Last Modified: 2008-01-09
It's an interview question. Any help is appreciated.

Thanks!
0
Comment
Question by:gromul
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 86

Accepted Solution

by:
jkr earned 2000 total points
ID: 17085339
See http://en.wikipedia.org/wiki/Virtual_method_table

Assuming

class foo {

public:

virtual void f1();
virtual void f2();

};

foo:
  +0: pointer to virtual method table of foo

Basically, it is only the pointer to the VTABLE if the class has no other (data) members - 4 bytes, that's it.

If you have

class foo {

public:

virtual void f1();
virtual void f2();

int n;
};

that'd be

  +0: pointer to virtual method table of foo
  +4: value of 'n'
0
 
LVL 11

Expert Comment

by:dbkruger
ID: 17085513
This is only a possible implementation, though it's extremely common, so I'd avoid saying this is THE layout.
It's conceivable that on some weird architecture they could do something else.

Good luck
0
 
LVL 4

Expert Comment

by:havman56
ID: 17097381
JKR  thanks for the link fom wikipedia

i learnt lot abt vtable  !!
0

Featured Post

Hire Technology Freelancers with Gigs

Work with freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely, and get projects done right.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: SunnyDark
This article's goal is to present you with an easy to use XML wrapper for C++ and also present some interesting techniques that you might use with MS C++. The reason I built this class is to ease the pain of using XML files with C++, since there is…
Container Orchestration platforms empower organizations to scale their apps at an exceptional rate. This is the reason numerous innovation-driven companies are moving apps to an appropriated datacenter wide platform that empowers them to scale at a …
The goal of the tutorial is to teach the user how to use functions in C++. The video will cover how to define functions, how to call functions and how to create functions prototypes. Microsoft Visual C++ 2010 Express will be used as a text editor an…
The viewer will be introduced to the technique of using vectors in C++. The video will cover how to define a vector, store values in the vector and retrieve data from the values stored in the vector.
Suggested Courses

649 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question