ID Number: Q11558
3.00 4.00 5.00 5.10 6.00 6.00a 6.00ax 7.00 | 5.10 6.00 6.00a
MS-DOS | OS/2
Summary:
In Microsoft C versions 5.0, 5.1, 6.0, 6.0a, 6.0ax, and C/C++ version
7.0, when converting a string into a floating-point number, the sscanf()
function is a good alternative to the atof() function.
More Information:
The atof() function will return a zero if the string cannot be
converted to a number, while sscanf() will return better error
information. This additional information can be used in conjunction
with matherr() to better handle errors.
The atof() function will not call matherr unless an actual math
exception occurred. The atof() function lacks a useful error return.
We suggest one of the following two methods for converting a string
to a floating-point number:
1. Validate the string to be converted prior to calling atof(). This
procedure includes checking the string for non-numeric characters
and making sure that the decimal point and signs are in the
correct places.
2. Use the sscanf() function. It is slower than atof, but it provides
better error return information.
Additional reference words: 5.00 5.10 6.00 6.00a 6.00ax 7.00