Variable Variables in Classes

[Alan Little]

class example {
var $Stage;

function example() {
$this->Stage = 'init';

$x = ???????;

echo $$x;
}
}

What do I put in $x so that $$x gives me "init"? 'Stage' doesn't work,
nor does 'this->Stage'.

--
Alan Little
Phorm PHP Form Processor

http://www.phorm.com/

[Ambush Commander]

Re: Variable Variables in Classes

It looks like in this particular case, $this->$x should be sufficient.
Otherwise, you may have to split up x into $x_object and $x_name
(exploding by -> should be sufficient) and calling $x_object->$x_name.
What you currently have, however, cannot be done.

[Rik]

Re: Variable Variables in Classes

Alan Little wrote:[color=blue]
> class example {
> var $Stage;
>
> function example() {
> $this->Stage = 'init';
>
> $x = ???????;
>
> echo $$x;
> }
> }
>
> What do I put in $x so that $$x gives me "init"? 'Stage' doesn't work,
> nor does 'this->Stage'.[/color]


Why use the $$ syntax?

<?php

class test{
var $string;
function text(){
$this->string = "This works";
$check = 'string';
echo $this->$check;
}
}
$a = new test();
$a->text();
?>

Grtz,
--
Rik Wasmus

[Alan Little]

Re: Variable Variables in Classes

Carved in mystic runes upon the very living rock, the last words of
Ambush Commander of comp.lang.php make plain:
[color=blue]
> It looks like in this particular case, $this->$x should be sufficient.[/color]

Thanks, but no.
[color=blue]
> Otherwise, you may have to split up x into $x_object and $x_name
> (exploding by -> should be sufficient) and calling $x_object->$x_name.
> What you currently have, however, cannot be done.[/color]

I'm not sure what you mean. What I'm trying to do is parse variables out
of a string and substitute them with the value. $x (in this example)
would hold the variable name extracted from the string. I'm trying to
figure out how to get to the value of that variable, from there.

--
Alan Little
Phorm PHP Form Processor

http://www.phorm.com/

[Rik]

Re: Variable Variables in Classes

Alan Little wrote:[color=blue]
> Carved in mystic runes upon the very living rock, the last words of
> Ambush Commander of comp.lang.php make plain:
>[color=green]
>> It looks like in this particular case, $this->$x should be
>> sufficient.[/color]
>
> Thanks, but no.
>[color=green]
>> Otherwise, you may have to split up x into $x_object and $x_name
>> (exploding by -> should be sufficient) and calling
>> $x_object->$x_name. What you currently have, however, cannot be done.[/color]
>
> I'm not sure what you mean.
> What I'm trying to do is parse variables
> out of a string and substitute them with the value. $x (in this
> example) would hold the variable name extracted from the string. I'm
> trying to figure out how to get to the value of that variable, from
> there.[/color]

That is exactly what it does.
$x = 'string'

$$x = $this->$x;
equals:
$string = $this->string;

$x is the variable name, $variable_name holds the value......

I don't get the problem?

What is the exact reason you're trying to accomplish? Maybe if you elaborate
some more, we get the picture. Why is it this doesn't suffice?

Grtz,
--
Rik Wasmus

[Alan Little]

Re: Variable Variables in Classes

Carved in mystic runes upon the very living rock, the last words of Rik
of comp.lang.php make plain:
[color=blue]
> Alan Little wrote:[color=green]
>> Carved in mystic runes upon the very living rock, the last words of
>> Ambush Commander of comp.lang.php make plain:
>>[color=darkred]
>>> It looks like in this particular case, $this->$x should be
>>> sufficient.[/color]
>>
>> Thanks, but no.
>>[color=darkred]
>>> Otherwise, you may have to split up x into $x_object and $x_name
>>> (exploding by -> should be sufficient) and calling
>>> $x_object->$x_name. What you currently have, however, cannot be
>>> done.[/color]
>>
>> I'm not sure what you mean.
>> What I'm trying to do is parse variables
>> out of a string and substitute them with the value. $x (in this
>> example) would hold the variable name extracted from the string. I'm
>> trying to figure out how to get to the value of that variable, from
>> there.[/color]
>
> That is exactly what it does.
> $x = 'string'
>
> $$x = $this->$x;
> equals:
> $string = $this->string;
>
> $x is the variable name, $variable_name holds the value......
>
> I don't get the problem?
>
> What is the exact reason you're trying to accomplish? Maybe if you
> elaborate some more, we get the picture. Why is it this doesn't
> suffice?[/color]

For example:

$this->animal = 'lamb';
$this->string = 'Mary had a little {{animal}}';

The goal is to extract 'animal' from the string (no problem), convert it
to 'lamb' and replace it in the string (again, no problem). The question
is, if I have 'animal', how do I get 'lamb'? In global space, I would
simply have 'animal' in a variable, and use $$var to get 'lamb'.

--
Alan Little
Phorm PHP Form Processor

http://www.phorm.com/

[Alan Little]

Re: Variable Variables in Classes

Carved in mystic runes upon the very living rock, the last words of Rik
of comp.lang.php make plain:
[color=blue]
> Alan Little wrote:[color=green]
>> class example {
>> var $Stage;
>>
>> function example() {
>> $this->Stage = 'init';
>>
>> $x = ???????;
>>
>> echo $$x;
>> }
>> }
>>
>> What do I put in $x so that $$x gives me "init"? 'Stage' doesn't work,
>> nor does 'this->Stage'.[/color]
>
> Why use the $$ syntax?
>
> <?php
>
> class test{
> var $string;
> function text(){
> $this->string = "This works";
> $check = 'string';
> echo $this->$check;[/color]

Ah, yes that works. Thank you.

--
Alan Little
Phorm PHP Form Processor

http://www.phorm.com/

[Kimmo Laine]

Re: Variable Variables in Classes

"Alan Little" <alan@n-o-s-p-a-m-phorm.com> wrote in message
news:Xns97C6A5C 373D05alanphorm com@216.196.97. 131...[color=blue]
> Carved in mystic runes upon the very living rock, the last words of Rik
> of comp.lang.php make plain:
>[color=green]
>> Alan Little wrote:[color=darkred]
>>> Carved in mystic runes upon the very living rock, the last words of
>>> Ambush Commander of comp.lang.php make plain:
>>>
>>>> It looks like in this particular case, $this->$x should be
>>>> sufficient.
>>>
>>> Thanks, but no.
>>>
>>>> Otherwise, you may have to split up x into $x_object and $x_name
>>>> (exploding by -> should be sufficient) and calling
>>>> $x_object->$x_name. What you currently have, however, cannot be
>>>> done.
>>>
>>> I'm not sure what you mean.
>>> What I'm trying to do is parse variables
>>> out of a string and substitute them with the value. $x (in this
>>> example) would hold the variable name extracted from the string. I'm
>>> trying to figure out how to get to the value of that variable, from
>>> there.[/color]
>>
>> That is exactly what it does.
>> $x = 'string'
>>
>> $$x = $this->$x;
>> equals:
>> $string = $this->string;
>>
>> $x is the variable name, $variable_name holds the value......
>>
>> I don't get the problem?
>>
>> What is the exact reason you're trying to accomplish? Maybe if you
>> elaborate some more, we get the picture. Why is it this doesn't
>> suffice?[/color]
>
> For example:
>
> $this->animal = 'lamb';
> $this->string = 'Mary had a little {{animal}}';
>
> The goal is to extract 'animal' from the string (no problem), convert it
> to 'lamb' and replace it in the string (again, no problem). The question
> is, if I have 'animal', how do I get 'lamb'? In global space, I would
> simply have 'animal' in a variable, and use $$var to get 'lamb'.
>[/color]


So again, wouldn't this work:

$var = 'animal';
$this->$var; //this is translated to $this->animal, which in turn gives you
'lamb' .


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

[Alan Little]

Re: Variable Variables in Classes

Carved in mystic runes upon the very living rock, the last words of
Kimmo Laine of comp.lang.php make plain:
[color=blue]
> "Alan Little" <alan@n-o-s-p-a-m-phorm.com> wrote in message
> news:Xns97C6A5C 373D05alanphorm com@216.196.97. 131...[color=green]
>> Carved in mystic runes upon the very living rock, the last words of
>> Rik of comp.lang.php make plain:
>>[color=darkred]
>>> Alan Little wrote:
>>>> Carved in mystic runes upon the very living rock, the last words of
>>>> Ambush Commander of comp.lang.php make plain:
>>>>
>>>>> It looks like in this particular case, $this->$x should be
>>>>> sufficient.
>>>>
>>>> Thanks, but no.
>>>>
>>>>> Otherwise, you may have to split up x into $x_object and $x_name
>>>>> (exploding by -> should be sufficient) and calling
>>>>> $x_object->$x_name. What you currently have, however, cannot be
>>>>> done.
>>>>
>>>> I'm not sure what you mean.
>>>> What I'm trying to do is parse variables
>>>> out of a string and substitute them with the value. $x (in this
>>>> example) would hold the variable name extracted from the string.
>>>> I'm trying to figure out how to get to the value of that variable,
>>>> from there.
>>>
>>> That is exactly what it does.
>>> $x = 'string'
>>>
>>> $$x = $this->$x;
>>> equals:
>>> $string = $this->string;
>>>
>>> $x is the variable name, $variable_name holds the value......
>>>
>>> I don't get the problem?
>>>
>>> What is the exact reason you're trying to accomplish? Maybe if you
>>> elaborate some more, we get the picture. Why is it this doesn't
>>> suffice?[/color]
>>
>> For example:
>>
>> $this->animal = 'lamb';
>> $this->string = 'Mary had a little {{animal}}';
>>
>> The goal is to extract 'animal' from the string (no problem), convert
>> it to 'lamb' and replace it in the string (again, no problem). The
>> question is, if I have 'animal', how do I get 'lamb'? In global
>> space, I would simply have 'animal' in a variable, and use $$var to
>> get 'lamb'.[/color]
>
> So again, wouldn't this work:
>
> $var = 'animal';
> $this->$var; //this is translated to $this->animal, which in turn
> gives you 'lamb' .[/color]

Yes, that works; I just didn't understand what AB was saying.

--
Alan Little
Phorm PHP Form Processor

http://www.phorm.com/

[Dikkie Dik]

Re: Variable Variables in Classes

> For example:[color=blue]
>
> $this->animal = 'lamb';
> $this->string = 'Mary had a little {{animal}}';
>
> The goal is to extract 'animal' from the string (no problem), convert it
> to 'lamb' and replace it in the string (again, no problem). The question
> is, if I have 'animal', how do I get 'lamb'? In global space, I would
> simply have 'animal' in a variable, and use $$var to get 'lamb'.
>[/color]
Ah. Why not use str_replace?

And when you are using classes, you could as easily define a Variable
class with a Name and a Value method, and even a ToTemplate method that
puts the two pairs of curly braces around them.

If this is for a template engine, you probably have the name/value pairs
in a "named" array. In that case, a str_replace in a foreach loop does
the job just fine.

Best regards

[Alan Little]

Re: Variable Variables in Classes

Carved in mystic runes upon the very living rock, the last words of
Dikkie Dik of comp.lang.php make plain:
[color=blue][color=green]
>> For example:
>>
>> $this->animal = 'lamb';
>> $this->string = 'Mary had a little {{animal}}';
>>
>> The goal is to extract 'animal' from the string (no problem), convert
>> it to 'lamb' and replace it in the string (again, no problem). The
>> question is, if I have 'animal', how do I get 'lamb'? In global
>> space, I would simply have 'animal' in a variable, and use $$var to
>> get 'lamb'.[/color]
>
> Ah. Why not use str_replace?[/color]

The replacing part is not a problem.
[color=blue]
> And when you are using classes, you could as easily define a Variable
> class with a Name and a Value method, and even a ToTemplate method
> that puts the two pairs of curly braces around them.[/color]

I'm not sure I follow you here. I'm trying to get value names *from* a
string, and then get the values for those names.
[color=blue]
> If this is for a template engine, you probably have the name/value
> pairs in a "named" array.[/color]

For some values, yes. But in other cases, such as error reporting, I need
to access an actual variable.

Anyway, I have it worked out now. But thank you for answering.

--
Alan Little
Phorm PHP Form Processor

http://www.phorm.com/