Re: asking for an opinion from the collective wisdom here

From:

terminator <farid.mehrabi@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Sat, 02 Jun 2007 15:35:47 -0700

Message-ID:

<1180823747.680416.113020@q75g2000hsh.googlegroups.com>

On Jun 3, 1:06 am, "Daniel T." <danie...@earthlink.net> wrote:

Devon Null <theronnights...@xgmailx.com> wrote:

I was wondering should the constructor be this:

Item( float weight = 0, bool set_can_equip = false, bool set_can_attack
= false, bool set_can_defend = false, bool set_can_drink = false, bool
set_can_eat = false, bool set_can_use = false, bool set_is_consumable =
false, bool set_is_magical = false );

with a constructor body like this in the cpp file:

Item::Item( float weight, bool set_can_equip, bool set_can_attack, bool
set_can_defend, bool set_can_drink, bool set_can_eat, bool set_can_use )
{
    item_weight = weight;
    can_equip = set_can_equip;
    can_attack = set_can_attack;
    can_defend = set_can_defend;
    can_drink = set_can_drink;
    can_eat = set_can_eat;
    can_use = set_can_use;
    is_consumable = set_is_consumable;
    is_magical = set_is_magical;
    need_set = "You need to set a description here!\n";
    desc_cleared = "The description has been cleared.\n";
    description.clear();
    description.push_back( need_set );
}

or this:

Item() : float weight( 0 ), bool can_equip( false ), bool can_attack(
false ), bool can_defend( false ), bool can_drink( false ), bool
can_eat( false ), bool can_use( false ), bool is_consumable( false ),
bool is_magical( false );

and lose the entire body of the constructor in the cpp file? I will need
to pass in parameters to override the defaults when I instantiate the
objects.

You can't lose the entire body of the constructor. However to answer the
underlying question, you should use the no argument constructor and just
initialize all the variables.

Item::Item() :
   weight( 0 ),
   can_equip( false ),
   can_attack( false ),
   can_defend( false ),
   can_drink( false ),
   can_eat( false ),
   can_use( false ),
   is_consumable( false ),
   is_magical( false )
{ }

At some point you will realize that your code is full of blocks that
check the various flags in this class and behave differently depending
on the setting of the flag. Then when you learn about polymorphism, you
will start writing better classes.- Hide quoted text -

- Show quoted text -

both forms can be used for ctors but the later is better when const
data members exist and the former is needed when members have to be
assigned assciated values:

int f(int,int);//A big function

class A{
public:
  const int m;
  int n,p;
  A(int i,int j):
    p(0),
    m(f(i,j))//const must be initialized here.
  {n=m;};/*if n is initailized in the initializer list f is called
twice which time expensive.*/
};