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Groups > comp.lang.c > #43948

Re: pass by address

From "Bill Cunningham" <nosapm@nspam.invalid>
Newsgroups comp.lang.c
Subject Re: pass by address
Date 2014-05-02 18:09 -0400
Organization A noiseless patient Spider
Message-ID <lk152a$1vf$1@dont-email.me> (permalink)
References <lk10j7$uhr$1@dont-email.me> <NxU8v.443052$1p2.55006@fx13.iad>

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"Lew Pitcher" <lew.pitcher@digitalfreehold.ca> wrote in message 
news:NxU8v.443052$1p2.55006@fx13.iad...

> Bill, think about this one a bit....
>
>  int a = 15;
>  int *p;
>
>  p = &a;
>
>  printf("%d\n",*p);
>  scanf("%d\n",p);

    That's really simple to interpret. Anyway. You are passing to printf the 
value stored at the pointee's address. With the scanf you are passing the 
pointer's address. Since pointers can only hold addresses. I would say the 
scanf  example is "pass by address" and the printf example is "pass by 
value". Is that right? But with scanf in your example; that's the first time 
I've ever seen the /pointer's/ address passed. Usually it's the /pointee's/ 
address using the &. But then that second parameter is an elipses and I 
haven't considered variable argument lists. Way over my head right now 
anyway.

Bill


Bill


Bill 

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Thread

pass by address "Bill Cunningham" <nosapm@nspam.invalid> - 2014-05-02 16:53 -0400
  Re: pass by address "Bill Cunningham" <nosapm@nspam.invalid> - 2014-05-02 17:03 -0400
    Re: pass by address "Bill Cunningham" <nosapm@nspam.invalid> - 2014-05-02 17:20 -0400
  Re: pass by address Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2014-05-02 17:58 -0400
    Re: pass by address "Bill Cunningham" <nosapm@nspam.invalid> - 2014-05-02 18:09 -0400
      Re: pass by address Barry Schwarz <schwarzb@dqel.com> - 2014-05-02 16:37 -0700
        Re: pass by address gazelle@shell.xmission.com (Kenny McCormack) - 2014-05-02 23:43 +0000
          Re: pass by address Richard <rgrdev_@gmail.com> - 2014-05-03 15:58 +0200
            Re: pass by address gazelle@shell.xmission.com (Kenny McCormack) - 2014-05-03 14:08 +0000
              Re: pass by address Barry Schwarz <schwarzb@dqel.com> - 2014-05-03 10:38 -0700
                Re: pass by address Richard <rgrdev_@gmail.com> - 2014-05-03 21:13 +0200
        Re: pass by address "Bill Cunningham" <nosapm@nspam.invalid> - 2014-05-03 01:46 -0400
        Re: pass by address "Bill Cunningaham" <nospam@nspam.invalid> - 2014-05-03 11:22 -0400
          Re: pass by address James Kuyper <jameskuyper@verizon.net> - 2014-05-03 12:13 -0400
          Re: pass by address Keith Thompson <kst-u@mib.org> - 2014-05-03 12:34 -0700
            Re: pass by address Richard <rgrdev_@gmail.com> - 2014-05-03 22:33 +0200
            Re: pass by address glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-05-03 21:21 +0000
              Re: pass by address "Bill Cunningham" <nospam@nspam.invalid> - 2014-05-04 00:08 -0400
                Re: pass by address Barry Schwarz <schwarzb@dqel.com> - 2014-05-03 21:52 -0700
                Re: pass by address Tonton Th <tth@nowhere.invalid> - 2014-05-04 08:44 +0000
                Re: pass by address Keith Thompson <kst-u@mib.org> - 2014-05-04 01:51 -0700
                Re: pass by address "Bill Cunningham" <nospam@nspam.invalid> - 2014-05-04 15:06 -0400
                Re: pass by address Barry Schwarz <schwarzb@dqel.com> - 2014-05-04 15:35 -0700
                Re: pass by address Richard <rgrdev_@gmail.com> - 2014-05-05 12:01 +0200
                Re: pass by address Barry Schwarz <schwarzb@dqel.com> - 2014-05-05 11:46 -0700
                Re: pass by address "Bill Cunningham" <nospam@nspam.invalid> - 2014-05-05 14:18 -0400
                Re: pass by address Barry Schwarz <schwarzb@dqel.com> - 2014-05-05 11:55 -0700
                Re: pass by address "Bill Cunningham" <nospam@nspam.invalid> - 2014-05-05 15:20 -0400
                Re: pass by address "Bill Cunningham" <nospam@nspam.invalid> - 2014-05-05 15:23 -0400
                Re: pass by address Ken Brody <kenbrody@spamcop.net> - 2014-05-06 11:02 -0400
                Re: pass by address "Bill Cunningham" <nospam@nspam.invalid> - 2014-05-06 14:46 -0400
                Re: pass by address Richard <rgrdev_@gmail.com> - 2014-05-05 12:00 +0200
                Re: pass by address Malcolm McLean <malcolm.mclean5@btinternet.com> - 2014-05-05 14:50 -0700
                Re: pass by address "Bill Cunningham" <nospam@nspam.invalid> - 2014-05-05 23:13 -0400
                Re: pass by address "Osmium" <r124c4u102@comcast.net> - 2014-05-05 23:09 -0500
                Re: pass by address "Bill Cunningham" <nospam@nspam.invalid> - 2014-05-06 08:55 -0400
                Re: pass by address Ken Brody <kenbrody@spamcop.net> - 2014-05-06 11:16 -0400
                Re: pass by address Richard <rgrdev_@gmail.com> - 2014-05-06 18:13 +0200
                Re: pass by address Kaz Kylheku <kaz@kylheku.com> - 2014-05-04 21:06 +0000
                Re: pass by address Kaz Kylheku <kaz@kylheku.com> - 2014-05-04 23:50 +0000
                Re: pass by address Keith Thompson <kst-u@mib.org> - 2014-05-04 12:36 -0700
                Re: pass by address "Bill Cunningham" <nospam@nspam.invalid> - 2014-05-05 14:21 -0400
                Re: pass by address Keith Thompson <kst-u@mib.org> - 2014-05-04 01:29 -0700
                Re: pass by address "Bill Cunningham" <nospam@nspam.invalid> - 2014-05-04 15:09 -0400
        Re: pass by address "Bill Cunningaham" <nospam@nspam.invalid> - 2014-05-03 11:32 -0400
  Re: pass by address Barry Schwarz <schwarzb@dqel.com> - 2014-05-02 16:43 -0700
    Re: pass by address "Bill Cunningham" <nosapm@nspam.invalid> - 2014-05-03 01:54 -0400
      Re: pass by address Richard <rgrdev_@gmail.com> - 2014-05-03 15:59 +0200
    Re: pass by address "Bill Cunningham" <nosapm@nspam.invalid> - 2014-05-03 02:08 -0400
      Re: pass by address "Bill Cunningaham" <nospam@nspam.invalid> - 2014-05-03 11:46 -0400
    Re: pass by address Kaz Kylheku <kaz@kylheku.com> - 2014-05-03 21:43 +0000

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