Calling the Constuctor

[Asimov]

Hi Chilli,

I am kinda relearning C++ after quite a long break, but I want to understand something about constructors.

Since following your tutorials I have been putting the code in the constructor like this.

Code: Select all

Missile::Missile()
	:x(400 ),
	y( 580 ),
	Fired ( false),
	Velocity ( 5 ),
	Explode ( false ),
	radius (0)
{
}

But when I used to program constructors I used to put the code in the curly brackets ie

Code: Select all

Missile::Missile()
{
int Explode= 10;
int radius =5;
}

Is this wrong, or are the functions of the curly brackets different?
My programs ued to run ok, but I would need to call the constructor to iniaialise variables.
Of course I used to keep my functions and classes together before as well.

Asimov

[uglypie]

The first type of syntax is called an initializer list. This is of interest if your class inherits from some base class, and you want something other than the default constructor to be called.

Ex.

Code: Select all

class Shape
{
public:
   Shape();
   Shape(int a);
};

class Rectangle : public Shape
{
public:
  Rectangle ()
  {
    // The Shape default constructor has already been called
    // Do some default stuff
  }
  Rectangle (int a)
  : Shape(a)
  {
    // The non-default constructor for Shape has been called
    // Initialize the other stuff
  }
};

For standard datatypes such as int and float, there's no difference.

[Asimov]

Hi Ghillie,

I have a lot of books on C++ and I don't think I have seen any where they put the initializer above the curly brackets, but it works so I will carry on doing it heh heh.

Thank you for clearing that up.

Asimov

[chili]

http://www.parashift.com/c++-faq-lite/c ... l#faq-10.6

[ghilllie]

Hi Ghillie,

I have a lot of books on C++ and I don't think I have seen any where they put the initializer above the curly brackets, but it works so I will carry on doing it heh heh.

Thank you for clearing that up.

Asimov

Hey looks like a bit missed the address

[ghilllie]

http://www.parashift.com/c++-faq-lite/c ... l#faq-10.6

Google OPS! bro not working...