Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c > #41339

Re: why printf("%d", arg) works with arg of type int, short, char

Show all headers | View raw

On 2014-03-04, Joe keane <jgk@panix.com> wrote:
> In article <20140302125139.273@kylheku.com>,
> Kaz Kylheku  <kaz@kylheku.com> wrote:
>>There are blatant inconsistencies like:
>>
>> printf("%f", double_var);
>>
>> scanf("%f", &double_var);  /* error */
>>
>> scanf("%lf", &double_var);  /* correct */
>
> First one should be "lf" ('long float').

Nope. %f takes double.

  "f,F A double argument representing a floating-point number is converted to
  decimal notation in the style [−]ddd.ddd, where the number of digits after
  the decimal-point character is equal to the precision specification."
  (ISO/IEC 9899:1999)

Where is %g and %e in scanf? If printf were consistent with scanf,
%g would scan the general printed representation that may use exponents
or not, %f would scan only [-]ddd.ddd, and %e only exponentials.

%f in printf perhaps doesn't stand for "floating". It means "fixed digits": 
in a sense the opposite of a "floating" decimal point with an exponent.

> When calling a varargs function it is legal to pass 'float' where
> 'double' is expected and vice versa.

When calling a varargs function, it is impossible to pass a float;
any such expression widens to a double.

> A lot of rules for 'float' were changed, just not this one.

Recently? In what way?

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

why printf("%d", arg) works with arg of type int, short, char jononanon@googlemail.com - 2014-03-01 01:29 -0800
  Re: why printf("%d", arg) works with arg of type int, short, char jononanon@googlemail.com - 2014-03-01 01:42 -0800
    Re: why printf("%d", arg) works with arg of type int, short, char jononanon@googlemail.com - 2014-03-01 01:54 -0800
      Re: why printf("%d", arg) works with arg of type int, short, char Barry Schwarz <schwarzb@dqel.com> - 2014-03-01 07:21 -0800
        Re: why printf("%d", arg) works with arg of type int, short, char gazelle@shell.xmission.com (Kenny McCormack) - 2014-03-01 15:51 +0000
          Re: why printf("%d", arg) works with arg of type int, short, char Richard <rgrdev_@gmail.com> - 2014-03-01 17:50 +0100
            Re: why printf("%d", arg) works with arg of type int, short, char gazelle@shell.xmission.com (Kenny McCormack) - 2014-03-01 18:36 +0000
  Re: why printf("%d", arg) works with arg of type int, short, char Melzzzzz <mel@zzzzz.invalid> - 2014-03-01 11:22 +0100
    Re: why printf("%d", arg) works with arg of type int, short, char jononanon@googlemail.com - 2014-03-01 02:39 -0800
    Re: why printf("%d", arg) works with arg of type int, short, char Keith Thompson <kst-u@mib.org> - 2014-03-01 19:44 -0800
  Re: why printf("%d", arg) works with arg of type int, short, char Keith Thompson <kst-u@mib.org> - 2014-03-01 02:34 -0800
    Re: why printf("%d", arg) works with arg of type int, short, char jononanon@googlemail.com - 2014-03-01 02:49 -0800
      Re: why printf("%d", arg) works with arg of type int, short, char James Kuyper <jameskuyper@verizon.net> - 2014-03-01 09:10 -0500
    Re: why printf("%d", arg) works with arg of type int, short, char <william@wilbur.25thandClement.com> - 2014-03-01 15:38 -0800
      Re: why printf("%d", arg) works with arg of type int, short, char Keith Thompson <kst-u@mib.org> - 2014-03-01 19:47 -0800
        Re: why printf("%d", arg) works with arg of type int, short, char <william@wilbur.25thandClement.com> - 2014-03-01 21:12 -0800
        Re: why printf("%d", arg) works with arg of type int, short, char Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2014-03-02 07:47 -0700
          Re: why printf("%d", arg) works with arg of type int, short, char Kaz Kylheku <kaz@kylheku.com> - 2014-03-02 20:53 +0000
            Re: why printf("%d", arg) works with arg of type int, short, char jgk@panix.com (Joe keane) - 2014-03-04 00:23 +0000
              Re: why printf("%d", arg) works with arg of type int, short, char Kaz Kylheku <kaz@kylheku.com> - 2014-03-04 00:33 +0000
                Re: why printf("%d", arg) works with arg of type int, short, char glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-04 00:45 +0000
                Re: why printf("%d", arg) works with arg of type int, short, char jgk@panix.com (Joe keane) - 2014-03-05 04:07 +0000
                Re: why printf("%d", arg) works with arg of type int, short, char Barry Schwarz <schwarzb@dqel.com> - 2014-03-05 10:07 -0800
  Re: why printf("%d", arg) works with arg of type int, short, char "BartC" <bc@freeuk.com> - 2014-03-01 11:12 +0000
    Re: why printf("%d", arg) works with arg of type int, short, char Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-03-01 10:54 -0500
      Re: why printf("%d", arg) works with arg of type int, short, char glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-01 18:55 +0000

csiph-web