tell about copy constructor

Question Posted / palnati

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tell about copy constructor..

Answer / sudha

A copy constructor is a special constructor in the C++
programming language used to create a new object as a copy
of an existing object.

There are 3 important places where a copy constructor is
called.

When an object is created from another object of the same
type
When an object is passed by value as a parameter to a
function
When an object is returned from a function

class B //With copy constructor
{
private:
char *name;
public:
B()
{
name = new char[20];
}
~B()
{
delete name[];
}
//Copy constructor
B(const B &b)
{
name = new char[20];
strcpy(name, b.name);
}
};

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6 Yes

0 No

tell about copy constructor..

Answer / madhu

Basic thing, copy constructor will be called whenever a copy
is made. and copy constructors are called when:
1. create a new object using existing object.
2. When is returning to caller.
3. When an object is passed by value as a parameter to a
function

Basically a default copy constructor will be created which
does bitwise copy also know as shallow copy.
This will become a problem when we are dealing with dynamic
memory allocation for variables and leads to dangling pointer.
To overcome we have to override by deep copy.

Is This Answer Correct ?

3 Yes

0 No

tell about copy constructor..

Answer / achal ubbott

e.g. Let there be a class

class Sample
{

};
suppose in main() you do like here

Sample obj1;
Sample obj2 = obj1; // Copy cons called here.
// then you call a function like this

fun(obj1); //Copy cons called here.

Is This Answer Correct ?

1 Yes

1 No

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