Issue 0137: Is printf("%.1f", -0.01) required to produce 0.0 , -0.0, or are both acceptable?

This issue has been automatically converted from the original issue lists and some formatting may not have been preserved.

Authors: Larry Jones, Project Editor (P.J. Plauger)
Date: 1994-04-30
Submitted against: C90
Status: Closed
Converted from: dr.htm, dr_137.html

Is printf("%.1f", -0.01) required to produce 0.0, -0.0, or are both acceptable?

Subclause 7.9.6.1 says that when the + flag is not specified, the result begins with a sign only when a negative value is converted. The description of the f conversion (also e and E) says that the value is rounded to the appropriate number of digits. Is the value used to determine the sign of the result the value before or after rounding?

Comment from WG14 on 1997-09-23:

Response

As specified in subclause 7.9.6.1 for the + flag, a negative value is being converted, so a minus sign is required. The intent is that the sign is determined prior to conversion.