The document discusses different types of constructors in C++ classes: 1. Default constructors are created by the compiler if no constructor is defined, and have no parameters. They initialize member variables. 2. Parameterized constructors allow passing different initialization values to objects, by passing arguments to the constructor. 3. Copy constructors copy the values of data members from one object to another by taking an object as a parameter. They are used to initialize a new object with the same values as an existing object.

1. Constructor, Destructor
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SADi, SHANTu

2. The Class Constructor:
A class constructor is a special member function of a class that is executed
whenever we create new objects of that class.
Unlike normal functions, constructors have specific rules for how they must be named:
1) Constructors should always have the same name as the class (with the same capitalization)
2) Constructors have no return type (not even void)
A constructor that takes no parameters (or has all optional parameters) is called a default constructor.

3. Here is an example of a class that has a
default constructor:
class A
{
int x;
public:
A(); //Constructor
};

4. Constructors can be defined either inside the class definition or outside class definition using
class name and scope resolution :: operator.
class A
{
int x;
public:
A(); //Constructor
};
A::A() // Constructor definition
{
i=1;
}

5. Constructors are of three
types :
1. Default Constructor
2. Parametrized
Constructor
3. Copy COnstructor
Types of Constructors

6. Default Constructor
Default constructor is the
constructor which doesn't
take any argument. It has
no parameter
Syntax :
class_name ()
{ Constructor Definition }
Example :
class Cube
{
int side;
public:
Cube()
{
side=10;
}
};
int main()
{
Cube c;
cout << c.side;
}
Output : 10

7. A default constructor is so important for initialization of
object members, that even if we do not define a constructor
explicitly, the compiler will provide a default constructor
implicitly.

8. Parameterized
Constructor
These are the
constructors with
parameter. Using this
Constructor you can
provide different values
to data members of
different objects, by
passing the appropriate
values as argument
Example :
class Cube
{
int side;
public:
Cube(int x)
{
side=x;
}
};
int main()
{
Cube c1(10);
Cube c2(20);
Cube c3(30);
cout << c1.side;
cout << c2.side;
cout << c3.side;
}
OUTPUT : 10 20 30

9. Copy Constructor
These are special type of Constructors which takes an object
as argument, and is used to copy values of data members of
one object into other object.