The constant use of isset() View as Markdown

While researching for this suggestion I found this rfc proposal regarding
ifsetor() ( http://wiki.php.net/rfc/ifsetor?s[]=issethttp://wiki.php.net/rfc/ifsetor?s%5B%5D=isset)
and it's rejection point was that it was currently not possible (
http://marc.info/?l=php-internals&m=108931281901389&w=2 )

But would it be possible to check for a value of a variable if it is set?

Since I often do (and see others do)

if(isset($_GET["foo"]) && $_GET["foo"] == "bar")
or even worse
if((isset($_GET["foo"]) && $_GET["foo"] == "bar") || (isset($_GET["baz"]) &&
$_GET["baz"] == "bat"))

to be able to do something like this

if(isset($_GET["foo"]) == "bar")
or
if(isset($_GET["foo"]) == "bar" || isset($_GET["baz"]) == "bat")

That isset (or some other language construct) would return the variable if
it were set and false if it was not.

Thanks for your time, i know this has probably been talked to death in one
form or other.

Ólafur Waage
olafurw@gmail.com

So if the variable is set and contains "false", we can't check it ?
And near same problem for 0, empty array and empty string.

How would you ever get false (the value, not the string) into a
request variable? (without setting it that way after the request init,
that is)

S

The error suppression was discussed in the rfc and yes it is not clean and
you could be suppressing something else inadvertently.

Yes the false value would be an issue with this, but for 0, empty array and
empty string is an issue with just about anything else in PHP already. Hence
=== if you want to be strict with it.

2009/5/12 Olivier B. php-dev.list@daevel.net

So if the variable is set and contains "false", we can't check it ?
And near same problem for 0, empty array and empty string.

But you can also use this syntax : (yes it's not very "clean")

if( @$_GET['foo'] === 'bar')
or
if( @$_GET['foo'] === 'bar' or @$_GET['baz'] === 'bat' )

Olivier

Ólafur Waage a écrit :

While researching for this suggestion I found this rfc proposal regarding
ifsetor() ( http://wiki.php.net/rfc/ifsetor?s[]=issethttp://wiki.php.net/rfc/ifsetor?s%5B%5D=isset
http://wiki.php.net/rfc/ifsetor?s%5B%5D=isset)
and it's rejection point was that it was currently not possible (
http://marc.info/?l=php-internals&m=108931281901389&w=2 )

But would it be possible to check for a value of a variable if it is set?

Since I often do (and see others do)

if(isset($_GET["foo"]) && $_GET["foo"] == "bar")
or even worse
if((isset($_GET["foo"]) && $_GET["foo"] == "bar") || (isset($_GET["baz"])
&&
$_GET["baz"] == "bat"))

to be able to do something like this

if(isset($_GET["foo"]) == "bar")
or
if(isset($_GET["foo"]) == "bar" || isset($_GET["baz"]) == "bat")

That isset (or some other language construct) would return the variable if
it were set and false if it was not.

Thanks for your time, i know this has probably been talked to death in one
form or other.

Ólafur Waage
olafurw@gmail.com

So this isset() behavior will only be available for request
variable, not for all variables ?

I'm not picking sides, but that seems to me like the overwhelmingly
popular use case.

S

2009/5/12 Brian Moon brian@moonspot.net

$foo = filter_input(INPUT_GET, "foo", FILTER_UNSAFE_RAW);

That would have a value if set or null if not set. It also allows you to
validate it using filters if you wanted to. This of course only works with
GPC variables, but it is a great solution.

Brian.

http://brian.moonspot.net/

Can this be turned into a userland function?

Olafur

While researching for this suggestion I found this rfc proposal regarding
ifsetor() ( http://wiki.php.net/rfc/ifsetor?s[]=isset<;
http://wiki.php.net/rfc/ifsetor?s%5B%5D=isset>;)
and it's rejection point was that it was currently not possible (
http://marc.info/?l=php-internals&m=108931281901389&w=2 )

But would it be possible to check for a value of a variable if it is set?

Since I often do (and see others do)

if(isset($_GET["foo"])&& $_GET["foo"] == "bar")
or even worse
if((isset($_GET["foo"])&& $_GET["foo"] == "bar") ||
(isset($_GET["baz"])&&
$_GET["baz"] == "bat"))

to be able to do something like this

if(isset($_GET["foo"]) == "bar")
or
if(isset($_GET["foo"]) == "bar" || isset($_GET["baz"]) == "bat")

That isset (or some other language construct) would return the variable if
it were set and false if it was not.

Thanks for your time, i know this has probably been talked to death in one
form or other.

Ólafur Waage
olafurw@gmail.com

2009/5/12 Ionut Gabriel Stan ionut.g.stan@gmail.com

2009/5/13 Ólafur Waage olafurw@gmail.com:

2009/5/12 Brian Moon brian@moonspot.net

$foo = filter_input(INPUT_GET, "foo", FILTER_UNSAFE_RAW);

That would have a value if set or null if not set. It also allows you
to
validate it using filters if you wanted to. This of course only works
with
GPC variables, but it is a great solution.

Brian.

http://brian.moonspot.net/

Can this be turned into a userland function?

If you're interested in userland code, then you have two solutions:

1. Make functions like GET, POST, COOKIE, SESSION and use them instead
   of the superglobals (functions are superglobal). An example:

---

// PHP < 5.3
function GET($key, $default = null) {
return isset($_GET[$key]) ? $_GET[$key] : $default;
}

// PHP >= 5.3
function GET($key, $default = null) {
return isset($_GET[$key]) ?: $default;
}

2. Use ArrayObject to override the superglobals in an auto_prepend_file:

---

$_GET = ArrayObject($_GET);

Anyway, these will save the trouble with the superglobals, not with
ordinary arrays.

Yes this will work with GPC variables but not with any other variable. And
passing values to it even feels right.

if(GET("foo") == "bar")

Olafur

While researching for this suggestion I found this rfc proposal
regarding
ifsetor() ( http://wiki.php.net/rfc/ifsetor?s[]=issethttp://wiki.php.net/rfc/ifsetor?s%5B%5D=isset
<
http://wiki.php.net/rfc/ifsetor?s%5B%5D=isset>;)
and it's rejection point was that it was currently not possible (
http://marc.info/?l=php-internals&m=108931281901389&w=2 )

But would it be possible to check for a value of a variable if it is
set?

Since I often do (and see others do)

if(isset($_GET["foo"])&& $_GET["foo"] == "bar")
or even worse
if((isset($_GET["foo"])&& $_GET["foo"] == "bar") ||
(isset($_GET["baz"])&&
$_GET["baz"] == "bat"))

to be able to do something like this

if(isset($_GET["foo"]) == "bar")
or
if(isset($_GET["foo"]) == "bar" || isset($_GET["baz"]) == "bat")

That isset (or some other language construct) would return the variable
if
it were set and false if it was not.

Thanks for your time, i know this has probably been talked to death in
one
form or other.

Ólafur Waage
olafurw@gmail.com

--
Ionut G. Stan
I'm under construction | http://igstan.blogspot.com/