NYCPHP Meetup

[Darryle Steplight]

Hi Mike,
   It kind of sounds like you are talking about two different things
or at least the confusion involves two different topics. Basically, if
you are going to use a Switch statement it's a good practice to keep
the case expression within quotation, if you want to get desired
results.

 Also, be very careful when doing ,
SWITCH($foo)
{
case  ' 5 ' :
case ' 6 ' :
    do execute some code...
break;
default:
break;
}

also 5 is an interger, but ' 5 ' is a string. So that will make a
difference when comparing it to $foo. Take a look at
http://us.php.net/intval for more details.


The above statement says if $foo equals 5 or 6 then execute some code.

On Tue, Sep 9, 2008 at 11:45 PM, Michael B Allen <ioplex at gmail.com> wrote:
> On Tue, Sep 9, 2008 at 10:56 PM, Hans Zaunere <lists at zaunere.com> wrote:
>>> Nevermind - $key is an int so 'foo' is being cast to an int which
>>> evaluates to 0.
>>>
>>> I think I would prefer that switch be a little more explicit.
>>>
>>> >        switch ($key) {
>>> >                case 'foo':
>>> >                case 'bar':
>>> >                        echo "[$key][$val]\n";
>>> >                        break;
>>> >        }
>>> > }
>>> >
>>> > $ php -f switch.php
>>> > [foo][1]
>>> > [bar][2]
>>> > [0][zap]
>>
>> Should switch be more explicit, or should the programmer? :)  Don't depend
>> on auto type casting...
>
> That's what I'm saying.
>
> In this case PHP looks at $key and sees (int)0. So now it auto type
> casts 'foo' to an int which for any string yields (int)0 and thus the
> case matches the 0 => 'zap' element unexpectedly. If switch used a
> typed comparison it would not auto type cast and it would compare
> (int)0 to (string)'foo' and because the types do not match I would get
> the expected results.
>
> But of course if switch used a typed comparison you would have to code
> something like:
>
>  $str = '5';
>  switch ($str) {
>      case 5:
>          // no match ?!
>          break;
>      case 'foo':
>          ...
>
> as:
>
>  $str = '5';
>  switch ($str) {
>      case 5:
>      case '5':
>          // ahhh, now it matches
>          break;
>      case 'foo':
>          ...
>
> with double cases which people would no doubt be hee'n and haw'n over to no end.
>
> M
>
> --
> Michael B Allen
> PHP Active Directory SPNEGO SSO
> http://www.ioplex.com/
> _______________________________________________
> New York PHP Community Talk Mailing List
> http://lists.nyphp.org/mailman/listinfo/talk
>
> NYPHPCon 2006 Presentations Online
> http://www.nyphpcon.com
>
> Show Your Participation in New York PHP
> http://www.nyphp.org/show_participation.php
>