How do you dynamically create private variables?

[thenewa2x]

This is a question for PHP v5.0.4.

How do you dynamically create private variables without predeclaring them as private in a class?

final class Dynamic
{
   private $sample1;

   public function __construct ( )
   {
      $array = (
        "sample2",
        "sample3",
        "sample4",
        "sample5",
        "sample6",
        "sample7",
        "sample8",
        "sample9",
        "sample10",
      );
      // Here's just some code that would make sense
      // but not necessarily work.
      foreach ( $array as $new_var )
      {
         private $this->$new_var = "";
      }
   }
}

The reason I want to do this is because I do not know what variables I am going to need to create. [tt]$array[/tt] can be changed to nearly everything.

---------------------------------------

http://www.visualactive.net/

 

[jemminger]

how about using an associative array?

final class Dynamic {
	private $vars;

	public function __construct () {

		$keys = array(
			"sample2",
			"sample3",
			"sample4",
			"sample5",
			"sample6",
			"sample7",
			"sample8",
			"sample9",
			"sample10"
		);

		foreach ($keys as $key) {
			$this->vars[$key] = null;
		}
	}

	function get($varname) {
		$val = null;
		if (array_key_exists($varname, $this->vars)) {
			$val = $this->vars[$varname]; 
		}
		return $val;
	}

	function set($varname, $val) {
		if (array_key_exists($varname, $this->vars)) {
			$this->vars[$varname] = $val;
		}
	}
}

$d = new Dynamic();
$d->set("sample2", "sample 2 data");
echo "<p>sample2 null?: " . is_null($d->get("sample2")) . "</p>";
echo "<p>sample22 null?: " . is_null($d->get("sample22")) . "</p>";

-jeff

http://www.jeffemminger.com

try { succeed(); } catch(E) { tryAgain(); } finally { rtfm(); }
i like your sleeves...they're real big

 

[hos2]

or

foreach ( $array as $new_var )
{
private $this->$$new_var = "";
}

 

[thenewa2x]

I have your way in consideration jemminger, thanks. But I still need to do something like my example. hos2, your example is almost the same is mine, it doesn't work. Thanks anyway.

Another other suggestions?

---------------------------------------

http://www.visualactive.net/

 

[mikefn]

Can you just use temp as a private variable?
Then from outside class you call with:
$c = new Dynamic();
$c->sample1 = ...


--
Mike FN
"8 out of 10 Owners who Expressed a Preference said Their Cats Preferred Web Programmer."

 

[hos2]

yep my example is almost the same but differs quite a lot because of the $$ assignment

suppose you have a variable
$test='var1';

then $$test='hallo';

echo $var1;

gives back "hallo"

perhaps is there something wrong with $this, I have never seen that before but I just copied you're code

perhaps
foreach ( $array as $new_var )
{
private $$new_var = "";
}

works better

 

[thenewa2x]

@hos2: i tried both your examples and i got this error on all versions of code that you given, and i even tried it using a single $: Parse error: parse error, unexpected T_PRIVATE

@mikefn: what? sorry but i didn't understand what you said. if i'm guessing correctly it looks like the same example jemminger gave me.

thanks guys, i still need help though!

---------------------------------------

http://www.visualactive.net/

 

[hos2]

perhaps because the variable type private doesn't exist in PHP , if you have some reference in a manual where it's used I would like to see but I can't find it on

http://nl2.php.net/manual/en/language.variables.scope.php

hey I don't know all the options php has to offer so when someone comes with a private declaration I guess that you did some research about this private type in php

 

[jemminger]

hos2, it is a feature of php5

http://us2.php.net/manual/en/language.oop5.visibility.php

-jeff

http://www.jeffemminger.com

try { succeed(); } catch(E) { tryAgain(); } finally { rtfm(); }
i like your sleeves...they're real big