A valid floating point number for atof
locale is formed by an optional sign character (
), followed by one of:
- A sequence of digits, optionally containing a decimal-point character (
), optionally followed by an exponent part (an
character followed by an optional sign and a sequence of digits).
prefix, then a sequence of hexadecimal digits (as in isxdigit
) optionally containing a period which separates the whole and fractional number parts. Optionally followed by a power of 2 exponent (a
character followed by an optional sign and a sequence of hexadecimal digits).
(ignoring case), where sequence
is a sequence of characters, where each character is either an alphanumeric character (as in isalnum
) or the underscore character (