passing variables to a class...

[toshog]

hi all,

have a class that has the variable $this->var = ""; decleared in the class' constructor...
and then i have this:
print $this->var;

when i call the class i do:
require('Class.php');
$newClass = new Class();
$newClass->var=5;

when i run the three lines above nothing shows up...

if i change the constructor like:
function Class($var) {
$this->var=$var;
}
and then do:
requiere('Class.php');
$newClass = new Class(5);

it works fine....

my question is why the first version isn't working? isn't $newClass->var=5; setting $this->var; for $newClass()?.....

any thoughts appreciated...

thank you...

[laserlight]

class Classname {
	var $varname;
	function Classname($varname = '') {
		$this->varname = $varname;
	}

//other member functions
}

$myclass = new Classname;
$myclass->varname = 5;
echo $myclass->varname;

probably should output "5".
as would

$myclass = new Classname(5);
echo $myclass->varname;

though some would recommend creating a function to write the $varname member variable instead of using it directly in your script.

EDIT:
I decided to change the names a bit, safer than risking conflicts with keywords.

[toshog]

that's what i though...
but i can't explain this:
i have a class that's working using the first version above like this:

class Info {
var $file;	 	

//Class constructor

 function info() {
$this->file = "";
 }

if (!($fp = fopen($this->file, "r"))) {
     die("could not open input");


  print "uhh...  opened....";

}
}

and then calling it:

newInfo = new Info();
newInfo->file="somefile.txt";

this prints "uhh... opened..."....

i don't pass it here like new Info('somefile.txt')

how's this working?!... or why?....

[laserlight]

This is another example that might help, although personally it probably isnt particularly useful as an actual class:

class Info {
	var $file;
	var $fp;
	var $file_opened;

//Class constructor
function info($file = '') {
	$this->file = $file;
	if (strlen($this->file) > 0) {
		$this->fp = $this->openfile() OR die("Could not open input");
		$this->file_opened = true;
	} else {
		$this->file_opened = false;
	}
}

function setFile($file) {
	$this->file = $file;
}

function openFile() {
	return fopen($this->file, "r");
}

function isOpenFile() {
	return $this->file_opened;
}

function getPtr() {
	if ($file_opened)
		return $this->fp;
	else
		return false;
}
}

$new_info = new Info('somefile.txt');
if ($new_info->isOpenFile())
	echo 'yeah, file was opened';

//or another example
$new_info = new Info;
$new_info->setfile('somefile.txt');
$new_info->openfile();
if ($new_info->isOpenFile())
	echo 'ha, file is now open';

[toshog]

thanks....

so basically if i want to pass for example variables coming through POST from a form to the class constructor i have to do soemthing like this:
newClass = new Class($POST['var1'],$POST['var2'].....);

instead of:

newClass - new Class();
newClass->var1=$POST['var1'];
newClass->var1=$POST['var2'];

right?!

thanks...

[laserlight]

They are both effectively the same.
One initializes member variables with values in the constructor, the other assigns the values to the member variables in the script itself.

[toshog]

Originally posted by laserlight
They are both effectively the same.
One initializes member variables with values in the constructor, the other assigns the values to the member variables in the script itself.

BUT you CAN'T use these:
$newClass = new Class();
$newClass->var1=$POST['var1'];
$newClass->var1=$POST['var2'];
$newClass->var1=$_POST['var3'];
...........

IN the constructor..... so they are not the same.... to me... sorry i'm insisting - i just want to clear the class clouds in my brain...

thanks again....

[laserlight]

um, you can, a good method being by passing those as arguments when you instantiate the object.

[toshog]

Originally posted by laserlight
um, you can, a good method being by passing those as arguments when you instantiate the object.

ok.... you win...

thank you...