Object slicing

Object slicing

I have a program as bellow:

#include<iostream.h>
#include<conio.h>
class A
{
    public:
    int x;
    A()
    {
        x=10;
    }
};

class B:public A
{
     protected:
     int y;
     public:
     B()
     {
        y=30;
     }
};

void main()
{
    A obj1;
    B obj2;
    obj1=obj2;
    cout<<obj1.x;
    cout<<obj1.y;
    getch();
}

The error message is "y is not member of A"

Can any one solve this problem?

View Answers

August 23, 2012 at 3:55 PM

There is nothing to solve here. The error message displays correct that "y is not member of A".

When you assign a derived class's instance into the base class only that part, which are present in the base class are copied, rest are not copied. this is called Object Sliced. because here obj2 get sliced and stored in obj1.

The main reson for this is, it is not possible (or meaningful) in any statically typed language for a superclass instance to contain subclass member variables.









Related Tutorials/Questions & Answers:
Object slicing
Object slicing  I have a program as bellow: #include<iostream.h> #include<conio.h> class A { public: int x; A() { x=10; } }; class B:public A { protected: int y
object
object  is it possible to create object in the same class..?.   Yes, you can. class CreateObject { CreateObject(){ System.out.println("I have an object."); } public static void main(String[] args
Advertisements
object of object class
object of object class  what do u mean by "object of object class
object creation
object creation  when will java object is created? is it at runtime or compiletime
Object Oriented
Object Oriented  C++ is Purely object oriented or not .Then why java called purely object oriented
Object reference not set to an instance of an object
Object reference not set to an instance of an object  Object reference not set to an instance of an object
Session Object
Session Object  Why do we require Session Object?  Hello.... The session object is used by the developers to store and retrieve user's related data such as login details. The javax.servlet.http.HttpSession object
ArrayList object
ArrayList object  i have am ArrayList object it containg data base records in it, now i want to display this ArrayList object data in my jsp programe, plz help me
object as argument
object as argument  what happens when we pass a object into a method???if java is pass by value how does this makes a difference.....pllzzz give me more clarification on why we pass objects in a margument
Java object
Java object  Which class should you use to obtain design information about an object
Object Creations
Object Creations  String a[][]=new String[10][20]; The above line how many objects are created
Object
Object       An object...). In an object, variables store values for later use and methods are the unit... are the basic units of the object-oriented programming. Objects are the part of our day
Java object
Java object  What is mutable object and immutable object?  An Immutable object is a kind of object whose state cannot be modified after it is created. This is as opposed to a mutable object, which can be modified
Session Object
Session Object   What is the Max amount of information that can be saved in a Session Object ?   There is no such limit on the amount of information that can be saved in a Session Object. The only limit is the Session
object array
object array  Hi i have array that is object[] obj= { new string("hi"), new vector().add(10), new hashmap().setkey()} display(obj); display(object{[] obj) {} Now my question is what is the string length and how to retrieve
Vector object[]
Vector object[]  I want to create payslip in java public Vector...(); Object[] value = new Object[] {"Employee Name",f.ename.getSelectedItem()}; rec.add(value); value = new Object[] {"Mary-Kate Olsen", "Ashley
class and Object
(Object of B is referenced by A) Variable: a ThanksADS_TO_REPLACE_2
implect object
implect object  how i implment implect object   Hi Friend, Please visit the following links:ADS_TO_REPLACE_1 http://www.roseindia.net/help/java/o/jsp-implicit-objects.shtml http://www.roseindia.net/jsp
constructor or object
constructor or object  object or construct which create first?   A constructor is always created first. Here is an example: class Example { Example(String st){ System.out.println(st); } public
object and method
object and method  a college would like to automate managing courses offered to students. initially only three courses are involved. each courses has... and an application that creates the necessary object
Class and object
(); You are creating the object of subclass Thanks
Java Object
Java Object         Object is the basic entity of object oriented programming language. Object... properties of the class or its group. Java object is an instance of the class. It takes
What is an object's lock and which object's have locks?
What is an object's lock and which object's have locks?   Hi, What is an object's lock and which object's have locks? Thanks
View object in JSF
View object in JSF  What is view object
Java object clone
Java object clone  What is criteria for a object to get cloned
How to disable an HTML object?
How to disable an HTML object?  How to disable an HTML object
assign object properties
assign object properties  How do you assign object properties
Date object using JavaScript
Date object using JavaScript  What's the Date object using JavaScript
Potential leak of an object XCode
Potential leak of an object XCode  What is potential leak of an object XCode
implementation object in C
implementation object in C  how to create and implement an object in C
use of object tag
use of object tag  how to use object tag in html
Java object's lock
Java object's lock  What is an object's lock and which object's have locks
Session Object from request
Session Object from request  Why are we getting session object from request object? Why are we adding cookie object into response object? Why are we getting cookie object from request object? I know all methods are available its
Object relational Mapping
Object relational Mapping  Define ORM
Object creation - Ajax
Object creation  How we want to create an object that directly get data from server
create a new object in JavaScript
create a new object in JavaScript  How do you create a new object in JavaScript
create a new object in JavaScript
create a new object in JavaScript  How do you create a new object in JavaScript
Object class in java
Object class in java  want an example and with an explaination about equals() method in object class? Is equals() is similar
What is Light Object Mapping?
What is Light Object Mapping?  Hi, What is Light Object Mapping? Thanks
JSP Out Object
JSP Out Object  JSP Out Object?   out object denotes... of the object out is jsp.JspWriter. The out object "Javax.servlet.jsp.JspWriter". Methods of out Object:ADS_TO_REPLACE_1 clear() clearBuffer() flush() isAutoFlush
conver object to int
conver object to int  i have a method returns object but i need int how can convert ? notice:object not means string means object string str map.get(str)ADS_TO_REPLACE_1 returns object but i need an integer
ModuleNotFoundError: No module named 'object'
ModuleNotFoundError: No module named 'object'  Hi, My Python... 'object' How to remove the ModuleNotFoundError: No module named 'object'... to install padas library. You can install object python with following command
JSP Response Object
JSP Response Object  JSP response Object ?   The response object denotes the HTTP Response data. The result or the information of a request is denoted with this object. The response object handles the output
JSP Application Object
JSP Application Object  JSP Application Object?   Application Object is used to share the data with all application pages. Thus, all users share information of a given application using the Application object
java object class methods
java object class methods  What are the methods in Object class?  There are lots of methods in object class. the list of some methods are as- clone equals wait finalize getClass hashCode notify notifyAll
delete javascript object
delete javascript object  How to create and delete an object in JavaScript
Is Java object oriented?
Is Java object oriented?  Hi, Is Java object oriented? Thanks   Hi, Java is object oriented programming language. It is supports OPPS concepts: Object Class Inheritance Polymorphism Abstraction Encapsulation All
object creation - Java Beginners
object creation  I need object creation in depth(with stack,pc registers).Any one can provide me if possible with video/audio
JSP Session Object
JSP Session Object  JSP Session Object?   Session Object... or the interface name of the object session is http.HttpSession. The object session is written as: Javax.servlet.http.httpsession. The Session Object provides
stdclass object php - PHP
stdclass object php  I know that stdClass is an object in PHP. But can you please explain it? it will be really helpful if you can illustrate it with an example

Ads