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Groups > comp.lang.c > #14372

Re: Why C has Pointers.

From Kaz Kylheku <kaz@kylheku.com>
Newsgroups comp.lang.c
Subject Re: Why C has Pointers.
Date 2011-12-07 20:48 +0000
Organization A noiseless patient Spider
Message-ID <20111207123642.485@kylheku.com> (permalink)
References <curixinfotech.54dl3z@no-mx.forums.yourdomain.com.au> <86ednS4jNcaK8kLTnZ2dnUVZ8mmdnZ2d@giganews.com>

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On 2011-12-07, Vincenzo Mercuri <vincenzo.mercuri@hotmail.it> wrote:
> Il 07/12/2011 13:22, curixinfotech ha scritto:
>> hi
>> my Q is on the c language tell me now why c has pointers.
>> parshant
>>
>
> Hi,
>
> here is a short article that can give you a clue as to why and how:
> http://duramecho.com/ComputerInformation/WhyCPointers.html

This article claims to be about C, but then recommends the use of C++ features
new and delete instead of malloc and free.

I.e. this is about the C-like subset within C++ and not about C.

Also, it teaches the casting of the malloc return value.  This is required
in C++, but not in C. It's not a bad idea in C, but you have to remember to
#include <stdlib.h> (not mentioned anywhere in the article), which you might
not unless your C compiler is configured to warn about the use of undeclared
functions. (Whenever possible, find out how to get this warning if it's not
there by default.) Without a prior declaration of malloc, 
int *x = (int *) malloc(42) means "call the function int malloc(int)"
and not "call the function void *malloc(size_t)". The cast suppresses the
diagnostic about the int to (int *) conversion which would otherwise occur.

C++ does not permit calls to undeclared functions, and does not permit
conversions from void * without a cast: good features, but they are not present
in C.

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Thread

Why C has Pointers. curixinfotech <curixinfotech.54dl3z@no-mx.forums.yourdomain.com.au> - 2011-12-07 07:22 -0500
  Re: Why C has Pointers. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-12-07 04:35 -0800
  Re: Why C has Pointers. Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-12-07 07:58 -0500
    Re: Why C has Pointers. Mike Manilone <zhtx10@gmail.com> - 2011-12-07 13:15 +0000
      Re: Why C has Pointers. Bill Reid <hormelfree@gmail.com> - 2011-12-08 06:29 -0800
  Re: Why C has Pointers. Vincenzo Mercuri <vincenzo.mercuri@hotmail.it> - 2011-12-07 14:50 +0100
    Re: Why C has Pointers. Keith Thompson <kst-u@mib.org> - 2011-12-07 11:01 -0800
      Re: Why C has Pointers. Vincenzo Mercuri <vincenzo.mercuri@yahoo.it> - 2011-12-07 20:49 +0100
      Re: Why C has Pointers. Brian <nospam@nospam.com> - 2011-12-07 20:00 +0000
        Re: Why C has Pointers. James Kuyper <jameskuyper@verizon.net> - 2011-12-07 15:30 -0500
          Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-07 12:43 -0800
            Re: Why C has Pointers. Keith Thompson <kst-u@mib.org> - 2011-12-07 13:09 -0800
          Re: Why C has Pointers. Vincenzo Mercuri <vincenzo.mercuri@hotmail.it> - 2011-12-08 19:39 +0100
            Re: Why C has Pointers. James Kuyper <jameskuyper@verizon.net> - 2011-12-08 14:16 -0500
              Re: Why C has Pointers. Vincenzo Mercuri <vincenzo.mercuri@hotmail.it> - 2011-12-08 20:23 +0100
    Re: Why C has Pointers. Kaz Kylheku <kaz@kylheku.com> - 2011-12-07 20:48 +0000
      Re: Why C has Pointers. Vincenzo Mercuri <vincenzo.mercuri@yahoo.it> - 2011-12-07 22:07 +0100
      Re: Why C has Pointers. Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-12-10 07:34 +0000
  Re: Why C has Pointers. August Karlstrom <fusionfile@gmail.com> - 2011-12-07 16:16 +0100
  Re: Why C has Pointers. Borax Man <rotflol2@hotmail.com> - 2011-12-08 18:32 +1100
    Re: Why C has Pointers. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-12-08 00:20 -0800
      Re: Why C has Pointers. André Gillibert <MetaEntropy.removeThis@gmail.com> - 2011-12-08 13:44 +0100
        Re: Why C has Pointers. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-12-09 05:04 -0800
          Re: Why C has Pointers. gazelle@shell.xmission.com (Kenny McCormack) - 2011-12-09 14:59 +0000
            Re: Why C has Pointers. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-12-09 20:19 -0800
            Re: Why C has Pointers. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-12-10 07:36 -0800
  Re: Why C has Pointers. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-12-08 00:12 -0800
  Re: Why C has Pointers. Cong Wang <xiyou.wangcong@gmail.com> - 2011-12-15 07:26 +0000
  Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-17 08:51 -0800
    Re: Why C has Pointers. Barry Schwarz <schwarzb@dqel.com> - 2011-12-17 10:10 -0800
      Re: Why C has Pointers. ralph <nt_consulting64@yahoo.net> - 2011-12-17 14:28 -0600
        Re: Why C has Pointers. ralph <nt_consulting64@yahoo.net> - 2011-12-17 15:00 -0600
        Re: Why C has Pointers. Keith Thompson <kst-u@mib.org> - 2011-12-17 13:55 -0800
          Re: Why C has Pointers. ralph <nt_consulting64@yahoo.net> - 2011-12-17 18:27 -0600
            Re: Why C has Pointers. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-18 01:26 +0000
              Re: Why C has Pointers. ralph <nt_consulting64@yahoo.net> - 2011-12-17 22:34 -0600
                Re: Why C has Pointers. "Philip Lantz" <prl@canterey.us> - 2011-12-17 23:48 -0800
                Re: Why C has Pointers. superpollo <superpollo@tznvy.pbz> - 2011-12-18 11:06 +0100
                Re: Why C has Pointers. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-18 13:44 +0000
                Re: Why C has Pointers. pete <pfiland@mindspring.com> - 2011-12-18 11:05 -0500
                Re: Why C has Pointers. James Kuyper <jameskuyper@verizon.net> - 2011-12-18 11:50 -0500
                Re: Why C has Pointers. Keith Thompson <kst-u@mib.org> - 2011-12-18 13:10 -0800
                Re: Why C has Pointers. ralph <nt_consulting64@yahoo.net> - 2011-12-27 16:03 -0600
                Re: Why C has Pointers. Barry Schwarz <schwarzb@dqel.com> - 2011-12-27 14:40 -0800
                Re: Why C has Pointers. Keith Thompson <kst-u@mib.org> - 2011-12-27 15:08 -0800
                Re: Why C has Pointers. ralph <nt_consulting64@yahoo.net> - 2011-12-27 20:09 -0600
                Re: Why C has Pointers. Keith Thompson <kst-u@mib.org> - 2011-12-27 23:00 -0800
                Re: Why C has Pointers. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-12-28 02:53 -0800
                Re: Why C has Pointers. James Kuyper <jameskuyper@verizon.net> - 2011-12-28 08:39 -0500
                Re: Why C has Pointers. James Kuyper <jameskuyper@verizon.net> - 2011-12-27 18:14 -0500
                Re: Why C has Pointers. Keith Thompson <kst-u@mib.org> - 2011-12-27 15:36 -0800
                Re: Why C has Pointers. James Kuyper <jameskuyper@verizon.net> - 2011-12-27 18:53 -0500
                Re: Why C has Pointers. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-28 13:20 +0000
                Re: Why C has Pointers. John Bode <jfbode1029@gmail.com> - 2011-12-28 08:42 -0800
              Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-17 20:36 -0800
                Re: Why C has Pointers. Seebs <usenet-nospam@seebs.net> - 2011-12-18 04:56 +0000
                Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-17 21:37 -0800
                Re: Why C has Pointers. Seebs <usenet-nospam@seebs.net> - 2011-12-18 05:42 +0000
                Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-18 08:08 -0800
                Re: Why C has Pointers. Robert Wessel <robertwessel2@yahoo.com> - 2011-12-18 10:36 -0600
                Re: Why C has Pointers. Seebs <usenet-nospam@seebs.net> - 2011-12-18 18:50 +0000
                Re: Why C has Pointers. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-12-19 02:39 -0800
                Re: Why C has Pointers. gordonb.1i27q@burditt.org (Gordon Burditt) - 2011-12-21 22:34 -0600
                Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-19 07:56 -0800
                Re: Why C has Pointers. John Tsiombikas <nuclear@member.fsf.org> - 2011-12-19 18:38 +0000
                Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-19 13:47 -0800
                Re: Why C has Pointers. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-12-28 02:58 -0800
                Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-28 03:21 -0800
            Re: Why C has Pointers. Keith Thompson <kst-u@mib.org> - 2011-12-18 13:07 -0800
              Re: Why C has Pointers. "io_x" <a@b.c.invalid> - 2011-12-19 04:02 +0100
        Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-17 15:35 -0800
          Re: Why C has Pointers. ralph <nt_consulting64@yahoo.net> - 2011-12-17 18:41 -0600
        Re: Why C has Pointers. John Bode <jfbode1029@gmail.com> - 2011-12-19 05:14 -0800
      Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-18 09:50 -0800
      Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2012-01-09 15:48 -0800
        Re: Why C has Pointers. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-01-10 00:21 -0800
          Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2012-01-10 01:03 -0800
    Re: Why C has Pointers. Keith Thompson <kst-u@mib.org> - 2011-12-17 11:45 -0800
      Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-17 15:18 -0800
      Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-19 14:10 -0800
        Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-20 10:46 -0800
  Re: Why C has Pointers. "Skybuck Flying" <Windows7IsOK@DreamPC2006.com> - 2011-12-17 19:15 +0100
    Re: Why C has Pointers. "Skybuck Flying" <Windows7IsOK@DreamPC2006.com> - 2011-12-17 19:19 +0100
      Re: Why C has Pointers. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-12-19 02:48 -0800
  Re: Why C has Pointers. 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-18 11:05 -0800
    Re: Why C has Pointers. Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-12-19 02:48 -0800

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