Subj : Re: directly inputting numbers
To   : borland.public.cpp.borlandcpp
From : maeder@glue.ch (Thomas Maeder [TeamB])
Date : Thu Jul 17 2003 07:25 pm

"Michael Fruchter" <mfruchtr@yahoo.com> writes:

> Is there a way to directly input a number from a non-delimited text as
> opposed to reading in a certain amount of characters using "fgets" and
> converting to an integer using "atoi" (and then, if necessary, dividing
> by 10^x for x decimal places)?

You can use the Standard C++ iostream functionality, e.g.:

#include <iostream>
#include <istream>
#include <ostream>

int main()
{
  int i;
  if (std::cin >> i)
  {
    ; // do something useful with i
    return EXIT_SUCCESS;
  }
  else
  {
    std::cerr << "input failure\n";
    return EXIT_FAILURE;
  }
}

You can read values of other numerical types by simply substituting them for
int. If you have the text in a string already, you can use a
std::istringstream or a std::istrstream instead.


[Note that what I wrote above is ISO Standard C++ syntax. Even the latest
release of Borland C++ predates this standard by years. While the functionality
is supported, you will probably have to adjust the syntax a bit to make
Borland C++ accept this code.]

.