Re: array of objects of parametrized constructor

From:
Ian Collins <ian-news@hotmail.com>
Newsgroups:
comp.lang.c++
Date:
Wed, 04 May 2011 21:24:37 +1200
Message-ID:
<92ckamFj04U1@mid.individual.net>
On 05/ 4/11 09:11 PM, Alf P. Steinbach /Usenet wrote:

* Ian Collins, on 04.05.2011 00:18:

On 05/ 4/11 07:29 AM, Alf P. Steinbach /Usenet wrote:

* asit, on 03.05.2011 20:32:

consider this class

class A
{
     int a;
public:
     A(int x):a(x)
     {
         cout<<"Parametrized constructor"<<endl;
     }
};

How can I create array of objects ??

I can't add the default constructor and overload the parametrized
constructor.


The simplest solution is to use std::vector, from the<vector> header.

E.g.

       std::vector<A> myArray;

       myArray.push_back( A( 1 ) );
       //...

And that's what you should be doing anyway, as a beginner. Don't mess around
with raw arrays. For that matter, don't add assembly language stubs either. ;-)


In this case, using a temporary array as a helper would be fine:

    A tmp[] = { 1,2,3,4 };
    std::vector<A> a(tmp, tmp+(sizeof(tmp)/sizeof(A)) );


I disagree.

Even an experienced programmer like yourself gets it, well not technically wrong
but pretty imperfect. :-(

If done, it would better look like this:

      int const tmp[] = { 1,2,3,4 };
      std::vector<A> a(tmp, tmp+(sizeof(tmp)/sizeof(*tmp)) );


You've been secretly reading c.l.c, haven't you Alf??

--
Ian Collins

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