##### Synopsis

    #include <stdlib.h>
    double atof(const char *nptr);

##### Description

atof converts the initial portion of the string pointed to by nptr to a double representation.

atof does not affect the value of errno on an error. If the value of the result cannot be represented, the behavior is undefined.

Except for the behavior on error, atof is equivalent to `strtod(nptr, (char **)NULL)`.

atof returns the converted value.

##### Portability

atof conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).

##### See Also

strtod