NAME

get_double - prompts user for a line of text from stdin and returns the equivalent double

SYNOPSIS

#include <cs50.h>

double get_double(const char *format, ...);

DESCRIPTION

Prompts user for a line of text from standard input and returns the equivalent double as precisely as possible; if text does not represent a double or would cause underflow or overflow, user is reprompted.

The prompt is formatted like printf(3).

RETURN VALUE

Returns the double equivalent to the line read from stdin in [DBL_MIN, DBL_MAX), as precisely as possible. If line can’t be read, returns DBL_MAX.

EXAMPLE

 /**
  * Returns the quotient of two doubles, or DBL_MAX on error.
  */
  double divide_doubles(void)
  {
      // read double from stdin
      double d = get_double("Enter a double: ");

      // make sure we read one successfully
      if (d == DBL_MAX)
      {
          return DBL_MAX;
      }

      double e = get_double("What do you want to divide %lf by? ", d);

      // make sure we don’t divide by zero
      if (e == DBL_MAX || e == 0.0)
      {
          return DBL_MAX;
      }

      return d / e;

  }

SEE ALSO

get_char(3), get_float(3), get_int(3), get_long(3), get_string(3), printf(3)