Undefined Class

[vipsa]

Hi

 

I am a complete beginner to php programming and I need to learn it fast as I am not a youngster anymore. I have a book called php and mysql and I am working through it.

 

Creating static member variables I get an error Undefined class constant 'totalDonated'

 

The variable totalDonated is in fact defined in the class definition and here is the code:

<?php

class Donation

{

private $name;

private $amount;

 

static $totalDonated = 0;

static $numberOfDonors = 0;

 

function info()

{

$share = 100 * $this->amount / Donation::$totalDonated;

return "{$this->name} donated {$this->amount} ({$share}%)";

}

 

function __construct($nameOfDonor, $donation)

{

$this->name = $nameOfDonor;

$this->amount = $donation;

 

Donation::$totalDonated = Donation::$totalDonated + $donation;

Donation::$numberOfDonors++;

}

 

function __destruct()

{

Donation::$totalDonated = Donation::$totalDonated - $donation;

Donation::$numberOfDonars--;

}

}

?>

 

and here is the code to make use of the class:

 

<?php

include "include/donation.inc";

 

$donors = array(

new Donation("Nicholas", 85),

new Donation("Thomas", 55),

new Donation("James", 78),

new Donation("Jeff", 123),

new Donation("Sarah", 444)

);

 

foreach($donors as $donor)

print $donor->info() . "<br";

 

$total = Donation::totalDonated;

$count = Donation::numberOfDonors;

print "Total donations = {$total}<br>";

print "Number of donors = {$count}<br>";

?>

 

So it makes no sense at all why I would get this error. Please if someone can help so I can learn this language as fast as possible.

 

Much appreciated.

[priti]

There are some error I noticed

 

$total = Donation::totalDonated;
$count = Donation::numberOfDonors;

 

Must be

 

$total = Donation::$totalDonated; //static variables
$count = Donation::$numberOfDonors; //static variables

 

Second In Destructor

 

Donation::$totalDonated = Donation::$totalDonated - $donation;
//$donation is not a class property !
Donation::$numberOfDonars--;    //variable name is wrong it must be "numberOfDonors" NOT numberOfDonars...check for "a"

 

You fix these thing I think your code will work for sure.

[Muddy_Funster]

Hi vipsa, please use code tags when posting code, and give us the full error message, including line number (with a pointer in the code, if you can, to that line).

 

Incidently, while inside the class, you should use self:: rather than Donation:: unless you've got a reason not to. (I think your book may be a bit dated, i.e. for PHP4) throw a "public" in front of the static as well (it's not needed, but php5 only allows for omitiion for legacy compatability)

[vipsa]

@priti: I did what you said but I don't understand what you mean by

Donation::$totalDonated = Donation::$totalDonated - $donation;

//$donation is not a class property ! (this line)

and after removing the destruct function it works but only prints one donor instead of 5. Am I missing something?

 

@Muddy_Funster: I will make sure to give more detail and full error description plus put the code inside code tags. I am new at this but I learn fast thx.

 

The book I have says for php5 but I also think it is a bit outdated. Can you recommend a good book? Also is there a website where I can find examples of php projects so I can practise creating them?

 

Thank you for the help.

[Muddy_Funster]

I personaly can not recomend any up-to-date books on PHP, been a while since I had much time for reading php. If you start a new thread about it though I'm sure there will be severall suggestions, both for books and for projects.

[cpd]

Unless you've configured your http server to regonise .inc files it won't interpret it as a PHP page. You currently have include "donation.inc";.

[Muddy_Funster]

file extension doesn't matter for includes/requires

[vipsa]

Thanks for your comments but it still does not solve my problem as the script does not want to run even after fixing the isues as mentioned in the beginning of this thread. Any help will be appreciated.

[Muddy_Funster]

could you let us see your updated code and maybe explain exactly what the problem is now?