That explains it perfectly, thanks you!
On Wed, Mar 31, 2010 at 12:40 AM, Tommy Pham <tommyhp2@xxxxxxxxx> wrote:
> On Tue, Mar 30, 2010 at 9:22 PM, Matty Sarro <msarro@xxxxxxxxx> wrote:
> > Hey all!
> > This is probably my second post on the list, so please be gentle. Right
> now
> > I am running through the "Heads First PHP and MySQL" book from O'Reilly.
> > It's been quite enjoyable so far, but I have some questions about some of
> > the code they're using in one of the chapters.
> >
> > Basically the code is retreiving rows from a DB, and I'm just not getting
> > the explanation of how it works.
> >
> > Here's the code:
> >
> > $result=mysqli_query($dbc,$query)
> >
> > while($row=mysqli_fetch_array($result)){
> > echo $row['first_name'].' '.$row['last_name'].' : '. $row['email'] . '<br
> > />';
> > }
> >
> > Now, I know what it does, but I don't understand how the conditional
> > statement in the while loop works. Isn't an assignment operation always
> > going to result in a "true" condition? Even if
> mysqli_fetch_array($result)
> > returned empty values (or null) wouldn't the actual assignment to $row
> still
> > be considered a true statement? I would have sworn that assignment
> > operations ALWAYS equated to true if used in conditional operations.
> > Please help explain! :)
> >
> > Thanks so much!
> > -Matty
> >
>
> http://www.php.net/manual/en/function.mysql-fetch-array.php
>
> "Returns an array of strings that corresponds to the fetched row, or
> FALSE if there are no more rows."
>
> while($row=mysqli_fetch_array($result)) is equivalent to this:
>
> $row=mysqli_fetch_array($result);
> while ($row){
>
> // do something
>
> $row=mysqli_fetch_array($result);
> }
>
> So, if $row is not equal to FALSE, the loop will happens.
>
