Classes and objects - please explain

[cyktor]

Hey all,

PHP is my first serious programming language (have some exp w/
javascript), so this notion of classes and objects confuses me. What's
a good way for me to understand this?

-cyktor

[whiskey]

Technically speaking, in JavaScript you don't have classes, but only
objects. Remember that it is a prototype based language.
Anyway, JavaScript won't help you much with understanding classes and
objects. Read some OOP books. But before you do, teach yourself some
procedural programming. Because *some* ain't enough. And, in the end,
most of the time you don't actually need OOP to go from A to B.

[Peter Fox]

Following on from 's message. . .

>Hey all,

PHP is my first serious programming language (have some exp w/
javascript), so this notion of classes and objects confuses me. What's
a good way for me to understand this?

-cyktor

Read a book?

--
PETER FOX Not the same since the e-commerce business came to a .
pe******@eminent.demon.co.uk.not.this.bit.no.html
2 Tees Close, Witham, Essex.
Gravity beer in Essex <http://www.eminent.demon.co.uk>

[cyktor]

By procedural programming, do you mean C? Please give me some
suggestions for procedural languages to learn.

-cyktor

[Harley]

A great text for PHP in general and OOP in particular is "Beginning PHP 5
and MySQL" by Jason Gilmore. A trip to the local bookstore or amazon.com
would provide you with more information than a reply in this forum.

Harley

P.S. If you want to use OOP skip PHP-4 and go directly to PHP-5 which has
much more functional OOP support.

<cy****@hotmail.comwrote in message
news:11**********************@b28g2000cwb.googlegr oups.com...

Hey all,

PHP is my first serious programming language (have some exp w/
javascript), so this notion of classes and objects confuses me. What's
a good way for me to understand this?

-cyktor

[IchBin]

cy****@hotmail.com wrote:

Hey all,

PHP is my first serious programming language (have some exp w/
javascript), so this notion of classes and objects confuses me. What's
a good way for me to understand this?

-cyktor

You can just look at the php manual:

version 4
http://www.php.net/manual/en/language.oop5.php

version 5
http://www.php.net/manual/en/language.oop.php

You can also just Google for OOP Tutorial

OOP and OOD terminology are the same in any language. Some languages
implement more of OOP\OOD than others.

--
Thanks in Advance... http://ichbin.9999mb.com
IchBin, Pocono Lake, Pa, USA http://weconsultants.phpnet.us
__________________________________________________ ____________________
'If there is one, Knowledge is the "Fountain of Youth"'
-William E. Taylor, Regular Guy (1952-)

[Moot]

cy****@hotmail.com wrote:

By procedural programming, do you mean C? Please give me some
suggestions for procedural languages to learn.

-cyktor

In most cases, an OOP language is also procedural. OOP is, at its
core, a fancy way to write modular and reusable procedural code,
because within all the layers of classes and functions, you still have
individual lines of code saying:
assign variable X
if something, then something
do this
do that

^- that is procedural code.

As for learning OOP, oh boy, where to begin? While it isn't strictly
an OOP book, I highly recommend going and getting a copy of The
Pragmatic Programmer and reading it cover to cover, and then once more
just to make sure you didn't miss anything. It won't teach you the
nuts and bolts of OOP, but it will lay a solid foundation of principles
that will help you understand the *why* of OOP in addition to the *how*.

[David]

A class is more specific name for the generic idea of an object.

Basically, it allows you to put code and data into a container and
tell the container to act on something and give me back a response. A
real example is a remote control which accepts the pressing of the
"power" key and then tells the TV to turn on/off.

YOu do need to get a basic book on object design if you plan to use
classes.

On 2 Nov 2006 07:17:31 -0800, cy****@hotmail.com wrote:

>Hey all,

PHP is my first serious programming language (have some exp w/
javascript), so this notion of classes and objects confuses me. What's
a good way for me to understand this?

-cyktor

[David]

This is a basic OO tutorial

http://www.aonaware.com/OOP1.htm

On 2 Nov 2006 07:17:31 -0800, cy****@hotmail.com wrote:

>Hey all,

PHP is my first serious programming language (have some exp w/
javascript), so this notion of classes and objects confuses me. What's
a good way for me to understand this?

-cyktor

[lawrence k]

cy****@hotmail.com wrote:

By procedural programming, do you mean C? Please give me some
suggestions for procedural languages to learn.

PHP without objects and classes is a good enough starting point to
learn procedural programming:

$howManyHats = 4;
$howManyHats = $howManyHats + 3;
setcookie("howManyHats", $howManyHats);

Things happen one at a time, straight down the page. You can use
functions, which means the code goes into those code blocks, but it is
still pretty straightforward.

With objects, you'd suddenly have some variables that are maybe set
inside of objects, and therefore the code is no longer so
straightforward. If HatObject sets a variable called $yardsOfCloth in
its constructor (let's say a value of 34):

$hatObject = new HatObject();
$clothInYards = $hatObject->getYardsOfCloth();
echo $clothInYards; // shows 34

[lawrence k]

David wrote:

A class is more specific name for the generic idea of an object.

Possibly you meant the opposite of this? An object is one specific
instance of a class. A class is a template for making certain kinds of
objects, but each object made from that class is its own specific
variable.

>
Basically, it allows you to put code and data into a container and
tell the container to act on something and give me back a response. A
real example is a remote control which accepts the pressing of the
"power" key and then tells the TV to turn on/off.

YOu do need to get a basic book on object design if you plan to use
classes.

On 2 Nov 2006 07:17:31 -0800, cy****@hotmail.com wrote:

Hey all,

PHP is my first serious programming language (have some exp w/
javascript), so this notion of classes and objects confuses me. What's
a good way for me to understand this?

-cyktor

[whiskey]

All this explanations, OOP at a glance, seem futile to me. OOP ain't
that simple. So a book is recommended. Not only about classes and
objects, but about interfaces, inheritance, polymorphism, and so on and
so forth. I'm working with classes and objects for 3 years now and I
still have problems with object oriented thinking.

And books, well... I can't think of a suggestion. My first language was
C++, and my first OOP steps were from "Jamsa's C/C++ Programmer's
Bible". The rest is history :-D

And, btw, [e-mail], learn a true programming language (not
JavaScript), such as C or C++, start with the beginning (procedural
programming) and then think of OOP. It's not something you learn in 24
hours.

[Pedro Graca]

whiskey wrote:

And, btw, [e-mail], learn a true programming language (not
JavaScript),

JavaScript /is/ a true programming language

http://javascript.crockford.com/javascript.html

--
I (almost) never check the dodgeit address.
If you *really* need to mail me, use the address in the Reply-To
header with a message in *plain* *text* *without* *attachments*.

[Rafe Culpin]

In article <11**********************@m73g2000cwd.googlegroups .com>,
al************@gmail.com (whiskey) wrote:

All this explanations, OOP at a glance, seem futile to me. OOP ain't
that simple. So a book is recommended. Not only about classes and
objects, but about interfaces, inheritance, polymorphism, and so on and
so forth. I'm working with classes and objects for 3 years now and I
still have problems with object oriented thinking.

And books, well... I can't think of a suggestion. My first language was
C++, and my first OOP steps were from "Jamsa's C/C++ Programmer's
Bible". The rest is history :-D

PHP 5 Objects, Patterns, and Practice.
Matt Zandstra, Apress
ISBN 1-59059-380-4

But it assumes existing knowledge of PHP and of procedural programming.

[whiskey]

Pedro Graca wrote:

JavaScript /is/ a true programming language

Sure it is true, rather a true *scripting* language.
One friend o'mine once said: "Life's hard without pointers..." :-)

Rafe Culpin wrote:

But it assumes existing knowledge of PHP and of procedural programming.

Of course, that's what I'm trying to say. Learn to do it in a
procedural way, and then start to better organise your application as
whole by using an OO aproach.

[Jerry Stuckle]

whiskey wrote:

Technically speaking, in JavaScript you don't have classes, but only
objects. Remember that it is a prototype based language.
Anyway, JavaScript won't help you much with understanding classes and
objects. Read some OOP books. But before you do, teach yourself some
procedural programming. Because *some* ain't enough. And, in the end,
most of the time you don't actually need OOP to go from A to B.

No, you don't *need* OOP. But you don't generally *need* structured
programming, either. You can do quite well with spaghetti code.

However - OOP is a means to build code that, if properly designed, is
more reusable and more maintainable.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================

[Jerry Stuckle]

whiskey wrote:

All this explanations, OOP at a glance, seem futile to me. OOP ain't
that simple. So a book is recommended. Not only about classes and
objects, but about interfaces, inheritance, polymorphism, and so on and
so forth. I'm working with classes and objects for 3 years now and I
still have problems with object oriented thinking.

And books, well... I can't think of a suggestion. My first language was
C++, and my first OOP steps were from "Jamsa's C/C++ Programmer's
Bible". The rest is history :-D

And, btw, [e-mail], learn a true programming language (not
JavaScript), such as C or C++, start with the beginning (procedural
programming) and then think of OOP. It's not something you learn in 24
hours.

OOP is quite easy - but it's a different way of thinking. And the longer
you've been doing procedural programming, the harder time you'll
probably have getting a handle on it.

Simply put, variables have states (values). Functions have behavior
(they do things). Objects have both states and behavior. You can save
one or more values in it (depending on how it's designed) and it has
behavior as defined by its public function.

Really, even an integer can be considered a class. You can instantiate
it to get a variable (object). It has state (it's value) and behavior
(add, subtract, etc.). Classes are just a way of extending what the
language predefines into something the programmer can define.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================

[Jerry Stuckle]

whiskey wrote:

Pedro Graca wrote:

>>JavaScript /is/ a true programming language

Sure it is true, rather a true *scripting* language.
One friend o'mine once said: "Life's hard without pointers..." :-)

Rafe Culpin wrote:

>>But it assumes existing knowledge of PHP and of procedural programming.

Of course, that's what I'm trying to say. Learn to do it in a
procedural way, and then start to better organise your application as
whole by using an OO aproach.

Don't let the "script" in Javascript fool you. Javascript is as much a
scripting language as PHP. Both are interpreted - one by the browser,
one by the server.

And yes, Javascript is a true programming language. OTOH, HTML is a
true scripting language.
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================