//en.cppreference.com/w/c/string/byte/atof.html
#include <stdlib.h>
#include <stdio.h>
int main(void)
{
printf("%g\n", atof(" -0.0000000123junk"));
printf("%g\n", atof("0.012"));
printf("%g\n", atof("15e16"));
printf("%g\n", atof("-0x1afp-2"));
printf("%g\n", atof("inF"));
printf("%g\n", atof("Nan"));
printf("%g\n", atof("1.0e+309")); // UB: out of range of double
printf("%g\n", atof("0.0"));
printf("%g\n", atof("junk")); // no conversion can be performed
}