Xref: utzoo comp.lang.c:15717 comp.sys.ibm.pc:23596
Path: utzoo!attcan!uunet!husc6!rice!uw-beaver!uw-june!ka
From: ka@june.cs.washington.edu (Kenneth Almquist)
Newsgroups: comp.lang.c,comp.sys.ibm.pc
Subject: Re: Microsoft C 5.1 question
Summary: "%.2d" and "%02d" are the same
Keywords: Printf formats
Message-ID: <7026@june.cs.washington.edu>
Date: 22 Jan 89 06:51:23 GMT
References: <104@rpi.edu> <198@broadway.UUCP> <6951@june.cs.washington.edu> <1587@csuna.UUCP>
Organization: U of Washington, Computer Science, Seattle
Lines: 24

abcscnge@csuna.UUCP (Scott "The Pseudo-Hacker" Neugroschl) writes:
> In article <6951@june.cs.washington.edu> ka@june.cs.washington.edu (Kenneth Almquist) writes:
> ]    printf("%2d:%.2d:%.2d", hour, minute, second);
> 
> How about
>      printf("%2d:%02d:%02d", hour, minute, second);

These behave identically.  A fair number of years ago, AT&T decided to
switch from the "%02d" format to the "%.2d" format.  A couple of reasons
for this may be:

     1) Conceptual simplicity.  The printf format has a precision field
	for use by the %s and the floating point formats; it makes sense
	to use this same field for integer formats rather than ignoring
	the precision and using some other method of getting zero padding.

     2) Flexibility.  Using the precision to specify the zero padding
	allows the field width to be used for its normal function even
	when zero padding is desired.

The "%02d" format will no doubt continue to work forever.  I've switched
to the new format because I don't expect newcomers to the C world want to
learn all the obsolete features of the language.
				Kenneth Almquist