question about symbol usage

spookweb

i've seen this in some recent code i have been backward engineering and I want to make sure what it does:

what is the purpose of " -> " (a hyphen followed by a greater than symbol) when used in an if statement such as:

if($arg->function($var))

TIA!

spookweb

maybl8r03

That would be OOP (Object Oriented Programming) implementation in PHP.

example of implementing

class c_helloworld()
{
   function c_helloworld() /// constructor
   {
       //initialize class
   }

   function show($strMessage="who me?")
   {
        $strResult = $this->showmessage("mini me {$strMessage}");
        return $strResult;
   }

   function showmessage($strMessage)
   {
        return "Hello {$strMessage}<br />";
   }
}

$objHello = new c_helloworld();
echo $objHello->show("yes me");

would produce

Hello mini me yes me

Refer to the PHP documentation on Classes and objects.

spookweb

Thanks maybl8r03 for your response...which brings me to another related item....

is it just me, or is the OOP concepts in PHP difficult to grasp, at least for users coming from a graphics (instead of programming) background?

I have been avoiding this part of PHP, knowing full well that one day i would have to swallow this nasty little pill. I have been reading the PHP manual pages on classes and objects, and it seems to me to be confusing at best.

Can anyone offer advice on understanding this better, or coming at it from a different angle.

Thanks...

spookweb

maybl8r03

There's a lot of smoke and mirrors with PHP's implementation of OOP - having said that I use it a lot in my projects. It makes things more manageable although there is a healthy debate out there on whether PHP should be doing objects at all - I am on the "should/must" camp.

If you are familiar with the traditional or proper way of doing objects then you will not be dissapointed when PHP 5 comes out. PHP 3 was terrible and PHP 4 is half baked but useable (as long as you know what to do) because in a sequential language (not event driven) such as PHP, there are limited ways that objects can be useful but used properly, it still boasts the basics advantage of OOP structures. Modularity, manageability and reusability 😉

I use objects in my projects to facilitate plugins and create base classes that connect up all the other required plugins to give the users as much functionality with as little complicated coding that I can muster.

We have other secondary coders (front-line tailoring) that code for their clients and they only need to modify the leaf classes and the html/xsl templates whereas all the atomic or core classes are common to all. In this sense it makes things much easier to maintain.

maybl8r03

Addendum: I mentioned PHP 5 (which uses the revamped Zend 2.0) engine. The major overhaul or improvement in this engine is it's adoption of "proper" classes and objects. A more robust structure for OOP. Read about it at: http://www.php.net/zend-engine-2.php

examancer

great example and link maybl8r03.

I don't think PHP's OOP model is any harder than any other OOP model really... OOP in general can be very hard to wrap you head around for a new programmer. I would suggest checking out the class examples in the PHP manual, and check out some of the user contributed classes in the code library for more examples. The only way I was able to learn it was to force myself to use other people's classes, and then it eventually started making sense.

examancer

grinds teeth and tries to wrap his head around everything new in PHP 5

God dammit... I finally understood PHP's OOP... now they gotta change it. But, the changes do look pretty promising.

maybl8r03

😃 I know what you mean!

Now all the nested call by reference (&) - will be even more confusing as we have to detangle them and change our understanding of "working on a reference" to "working on a copy" and back to "working on a reference" again... LOL

And as you said, the changes look promising.... even exciting!

I know all this flip-flop'ing will cause people to be afraid of touching OOP but in actual fact if you read closely they've manage to keep backwards compatibility to a maximum and the changes are mostly additions of features (or what I would like to call resurrection of features -- of what should be available to OOP in the first place).

So do not be afraid to jump in the pond spookweb!!!