renew() an array?

[pradeep]

Hello friends:

Say I allocate an array with
a = new int(100);

Later I want to grow the array to size 200. Do I need to allocate
another array and copy the first one to it? Is there a simpler approach
(like realloc() - my compiler doesn't recognize renew() as a function).

Thanks.

[Andrey Tarasevich]

Re: renew() an array?

pradeep wrote:

Say I allocate an array with
a = new int(100);

That does not allocate an array. This does

a = new int[100];

Later I want to grow the array to size 200. Do I need to allocate
another array and copy the first one to it?

Well, yes, as long as you are insisting on using 'new' to allocate arrays.

Is there a simpler approach
(like realloc() - my compiler doesn't recognize renew() as a function).

The simpler approach would be to use 'std::vector' and leave the details
to the implementation.

--
Best regards,
Andrey Tarasevich

[Antoninus Twink]

Re: renew() an array?

On 25 Apr 2008 at 22:15, pradeep wrote:

Hello friends:
>
Say I allocate an array with
a = new int(100);

I think you want square brackets.

Later I want to grow the array to size 200. Do I need to allocate
another array and copy the first one to it? Is there a simpler approach
(like realloc() - my compiler doesn't recognize renew() as a function).

No.

Why not use std::vector, which provides dynamic resizing via resize(),
insert(), and the like?

[santosh]

Re: renew() an array?

pradeep wrote:

Hello friends:
>
Say I allocate an array with
a = new int(100);
>
Later I want to grow the array to size 200. Do I need to allocate
another array and copy the first one to it? Is there a simpler
approach (like realloc() - my compiler doesn't recognize renew() as a
function).

This is a C++ question as far as I can see. Try comp.lang.c++ instead of
comp.lang.c.

[Walter Roberson]

Re: renew() an array?

In article <futlbk$sb3$1@a ioe.org>,
Andrey Tarasevich <andreytarasevi ch@hotmail.comw rote:

>pradeep wrote:

>Say I allocate an array with
>a = new int(100);

>That does not allocate an array. This does

a = new int[100];

This is comp.lang.c . The above is a syntax error in C.

To the original poster: 'new' is not part of C. Please consult
a newsgroup for whatever programming language you are using.
For example, if you are using C++ then comp.lang.c++ would be appropriate.
--
"The first draught serveth for health, the second for pleasure,
the third for shame, the fourth for madness." -- Sir Walter Raleigh

[Martin Ambuhl]

Re: renew() an array?

pradeep wrote:

Hello friends:
>
Say I allocate an array with
a = new int(100);

Then you want a language other than C. As that line stands, it is a
syntax error.

>
Later I want to grow the array to size 200.

Even in (shudder) the bloat-de-jure C++ language, that's the wrong way
to do it. Consider using the <off-topicvector class </off-topic>.

Do I need to allocate
another array and copy the first one to it? Is there a simpler approach
(like realloc() - my compiler doesn't recognize renew() as a function).

If it were a C compiler, it would have vomited at the earlier line of code,

[Keith Thompson]

Re: renew() an array?

pradeep <nospam@nospam. comwrites:

Say I allocate an array with
a = new int(100);
>
Later I want to grow the array to size 200. Do I need to allocate
another array and copy the first one to it? Is there a simpler
approach (like realloc() - my compiler doesn't recognize renew() as a
function).

This is a C++ question. It's also a frequently asked C++ question.
You'll likely find all the information you need in the C++ FAQ at
<http://www.parashift.c om/c++-faq-lite/>, particularly section 16. If
you have further questions, please post to comp.lang.c++.

--
Keith Thompson (The_Other_Keit h) <kst-u@mib.org>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"