variables type

[Tijs Verwest]

It's a newbie question...

Is it possible to type variable in PHP inspite this is a loose type
language. Or would that be required in some cases?

[Kimmo Laine]

Re: variables type

"Tijs Verwest" <stephane.volle t@bluewin.ch> wrote in message
news:443c0c23$1 _2@news.bluewin .ch...[color=blue]
> It's a newbie question...
>
> Is it possible to type variable in PHP inspite this is a loose type
> language.[/color]


Variables do have some sort of typing but as you know it's very loose. if a
particular variable happens to be an integer and you assign an array to it,
it becomes an array. There are ways of detecting the type of a variable and
there are ways of casting a variable to certain type.

A little exaple of ways of manipulating the type.
<?php

$foo; // Now we have no idea what this is.
$foo = "bar"; // assigning a string to it makes it a string.
echo gettype($foo); // this prints the type. string
$bar = (int)$foo; // now we assign the string into $bar but typecast it to
int.
if(is_int($bar) ) echo "$bar is an integer"; // is it int?
else echo "wtf? $bar is not an int, it's ". get_type($bar);

?>

I recommend you to read this: http://fi2.php.net/manual/en/ref.var.php
[color=blue]
> Or would that be required in some cases?[/color]

It depends on your code. Sometimes it's crucial, sometimes not. If and when
it is, I use type casts to make sure something is of some type, for example
when inserting a number intoa database I make sure it's a number to avoid
errors. A simple type cast takes care of it.

--
"ohjelmoija on organismi joka muuttaa kofeiinia koodiksi" -lpk
spam@outolempi. net | Gedoon-S @ IRCnet | rot13(xvzzb@bhg byrzcv.arg)

[Erwin Moller]

Re: variables type

Tijs Verwest wrote:
[color=blue]
> It's a newbie question...
>
> Is it possible to type variable in PHP inspite this is a loose type
> language. Or would that be required in some cases?[/color]

Hi,

PHP has the concept of types, however:

From manual:
-----------------
The type of a variable is usually not set by the programmer; rather, it is
decided at runtime by PHP depending on the context in which that variable
is used.
-----------------

Read more here:

http://nl2.php.net/manual/en/language.types.php

Also be sure to follow the link to 'Type Juggling'.

So, unlike strongtyped languages, in PHP you let the interpretation of the
type of a variable to the language itself.
In case of doubt you can ALWAYS cast to the type you want/demand.

for example:
$myInt = (int)$unclearVa lue;

You can also test for types, but that is all in the documentation.

In my experience, you do need the casting sometimes, but once you get
familiar with PHP it is easy to spot where.
If in doubt: just cast.

Good luck,
Erwin Moller

[fletch]

Re: variables type

I use a notation, whose name I can't remember, to show what type the
variable should be.

$iInt
$aArray
$bBool
$mMixed - could be anything
$sString
$oObj

so I can do loops like
while(list($sFi eldName,$aField Def)=each($aFie lds)){}

Also, some regulalry used objects are given their own prefix as opposed
to a general 'o'

Checking function declarations becomes much easier also.

[Erwin Moller]

Re: variables type

fletch wrote:
[color=blue]
> I use a notation, whose name I can't remember, to show what type the
> variable should be.
>
> $iInt
> $aArray
> $bBool
> $mMixed - could be anything
> $sString
> $oObj
>
> so I can do loops like
> while(list($sFi eldName,$aField Def)=each($aFie lds)){}
>
> Also, some regulalry used objects are given their own prefix as opposed
> to a general 'o'
>
> Checking function declarations becomes much easier also.[/color]

Hi,

I think that is called Hongarian Notation.
Not sure either. :-)

Erwin

[Jerry Stuckle]

Re: variables type

Erwin Moller wrote:[color=blue]
> fletch wrote:
>
>[color=green]
>>I use a notation, whose name I can't remember, to show what type the
>>variable should be.
>>
>>$iInt
>>$aArray
>>$bBool
>>$mMixed - could be anything
>>$sString
>>$oObj
>>
>>so I can do loops like
>>while(list($s FieldName,$aFie ldDef)=each($aF ields)){}
>>
>>Also, some regulalry used objects are given their own prefix as opposed
>>to a general 'o'
>>
>>Checking function declarations becomes much easier also.[/color]
>
>
> Hi,
>
> I think that is called Hongarian Notation.
> Not sure either. :-)
>
> Erwin
>[/color]

Close. It's "Hungarian" . :-)


--
=============== ===
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attgl obal.net
=============== ===

[Erwin Moller]

Re: variables type

Jerry Stuckle wrote:
[color=blue]
> Erwin Moller wrote:[color=green]
>> fletch wrote:
>>
>>[color=darkred]
>>>I use a notation, whose name I can't remember, to show what type the
>>>variable should be.
>>>
>>>$iInt
>>>$aArray
>>>$bBool
>>>$mMixed - could be anything
>>>$sString
>>>$oObj
>>>
>>>so I can do loops like
>>>while(list($ sFieldName,$aFi eldDef)=each($a Fields)){}
>>>
>>>Also, some regulalry used objects are given their own prefix as opposed
>>>to a general 'o'
>>>
>>>Checking function declarations becomes much easier also.[/color]
>>
>>
>> Hi,
>>
>> I think that is called Hongarian Notation.
>> Not sure either. :-)
>>
>> Erwin
>>[/color]
>
> Close. It's "Hungarian" . :-)
>[/color]

:-)

Ok, thx.
It's not easy being Dutch on the net. ;-)

Regards,
Erwin Moller

[Jerry Stuckle]

Re: variables type

Erwin Moller wrote:[color=blue]
> Ok, thx.
> It's not easy being Dutch on the net. ;-)
>
> Regards,
> Erwin Moller
>[/color]

:-)

--
=============== ===
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attgl obal.net
=============== ===