OOPS - Why the copy constructor is having a (&) variable as parameter?

GeekInterview.com > Tech FAQs > OOPS

Go To First | Previous Question | Next Question

OOPS | Question 253 of 255

Why the copy constructor is having a (&) variable as parameter?

Total Answers and Comments: 2

Last Update: January 16, 2008 Asked by: preetha varma

Sponsored Links

Best Rated Answer

—

No best answer available. Please pick the good answer available or submit your answer.

November 28, 2007 07:39:54

vedjai

Member Since: November 2007 Contribution: 1

RE: Why the copy constructor is having a (&) variable as parameter?

the work of the copy constructor is to create a new object of the same class and copy the value of the data members from the calling object into this new object data members. When we pass some variables as input parameters, the copy constructor gets called to create local copies of the objects. If the & is ignored then the Copy Constructor will keep calling itself and will go into an endless loop. To avoid this endless loop situation, we have to pass the parameter into the copy constructor as a reference.

Is this answer useful? Yes | No

January 16, 2008 21:18:29

irfan.omair

Member Since: January 2008 Contribution: 2

RE: Why the copy constructor is having a (&) variable as parameter?

It can be better explained in this way also.

Thumb Rule When a copy constructor is called ? : when any object is created and it is being initialized with otherObject of same type Copy constructor is called. Blv me this is is only one way how copy constructor is called.

Now lets understand one thing with an example .

int foo ( int age) { } and this function is called from main () { int m=10; foo(m); }
now here in function foo(int age) , the varible age is being created and initialiezed with another value which is being send from main with name "m" .
similarly in the case of copyConstructor

class A { ..... A(A&a){}..}
if A(A&a) would be A(A a) , then here in A(A a) an object a is being created and initialiezed with anoher object . and it will again call copy constructor as per the thumb Rule above. then again same story and this will continue untill the applicationsl stack is not overflowed. and program will fianaly crash.

Is this answer useful? Yes | No

OOPS Tutorials

Object oriented programming OOP is a computer science term used to characterize a programming language that began development in the 1960’ s The term object oriented programming’ was originally coined by Xerox PARC to designate a computer application that describes the methodol

What happens when a variable is not initialized in main function?

When a variable is not initialized in main function it contains garbage value. This can be well seen from the example below main() { int x; printf(“%d”,x); z= sample() } sample() { printf(“Testing program”); } Output is   &n

What happens when a variable is not declared in function definition?

Generally in C program the function definition and calling takes the form as given below: main() { int x,y,z; z=sample(x,y); printf(“%d”,z); } sample(x1,y1) int x1,y1; { int z1; z1= x1 - y1; return(z1); } Here what happens is the values x, y gets passed to x1,y1

Variable, Constants and Data types in C++

Variable Constants and Data types in C In this C tutorial you will learn about variable constants and data types in C rules for defining variable name short int int long int float double long double char bool declaring variables and constants mosgoogle Variables A variable is the storage location in

The Inheritance Concept In OOPs

The Inheritance Concept In OOPs In object oriented programming objects will be characterised by classes It is possible to learn a lot about an object based on the class it belongs to Even if you are not familiar with the name Maybach If I told you it is a car you would immediately know that it has f

Understanding The Message Concept In OOPs

Understanding The Message Concept In OOPs To understand object oriented programming you will need to become familiar with messages As the name implies a message is a process in which software objects will communicate with one another Because of this having one object is not enough mosgoogle An objec

Basic concepts of OOPS and Structure of C++ program

Basic concepts of OOPS and Structure of C program In this tutorial you will learn about Objects Classes Inheritance Data Abstraction Data Encapsulation Polymorphism Overloading Reusability Before starting to learn C it is essential that one must have a basic knowledge of the concepts of Object orie