Stupid (yet simple) error

I have this code:

int i = -5;
while ((i<0) & (i>=100))
i = Integer.parseInt(stdin.readLine());
// stdin is a BufferedReader

It's supposed to repeatedly read the users input until the user types a
number between 0 and 100. However, whenever I start the program it accepts
that i=-5 and an error occurs because of this.
Why?

Gajo

gajo

"gajo" wrote...

> int i = -5;
> while ((i<0) & (i>=100))
> i = Integer.parseInt(stdin.readLine());
> // stdin is a BufferedReader
>
> It's supposed to repeatedly read the users input until
> the user types a number between 0 and 100.

The condition you have written can *never* evaluate to true. (i can never be
*both* less than zero *and* greater or equal to 100).

I guess you're looking for:

while ((i < 0) || (i >= 100))

Bjorn A

Bjorn Abelli

I should probably say something like "arrrrgh!" now, right?

gajo

sok, many of us have been in your shoes before


"gajo" <> wrote in message news:boou74$i4$...
> I should probably say something like "arrrrgh!" now, right?
>
>

nos

gajo wrote:
> I have this code:
>
> int i = -5;
> while ((i<0) & (i>=100))
> i = Integer.parseInt(stdin.readLine());
> // stdin is a BufferedReader
>
> It's supposed to repeatedly read the users input until the user types a
> number between 0 and 100. However, whenever I start the program it accepts
> that i=-5 and an error occurs because of this.
> Why?

I don't know what you mean by "an error occurs", but it's clearly not
possible to satisfy the condition "((i < 0) & (i >= 100))", so the input
will never actually happen. Perhaps you meant "|" (and it's better to
use the short-cutting operators unless you have a specific reason not
to, so I'd use "||" instead.)

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