what is the -> operator?

[MikeB]

I'm looking at some code and found the -operator. In looking at the
PHP manual at php.net, I can't find a description of what it does. I
can find an example of where it is used, like on this page:
http://us2.php.net/manual/en/language.types.object.php

In the sample code like this:

<?php
class foo
{
function do_foo()
{
echo "Doing foo.";
}
}

$bar = new foo;
$bar->do_foo();
?>

But what does it do?

The code that triggered this search was this code:

function __construct()
{
$this->soap_client = new SoapClient($this->wsdl);
}
In the above, is the $this equivalent to "this" in other languages,
ie. an instance of the object itself? Again, a search of the manual at
php.net did not yield anything for the $this variable.

Thanks.

[Egbert Teeselink]

On Jun 1, 5:45*pm, MikeB <[e-mail]:

I'm looking at some code and found the -operator. In looking at the
PHP manual at php.net, I can't find a description of what it does. I
can find an example of where it is used, like on this page:http://us2.php.net/manual/en/language.types.object.php

In the sample code like this:

<?php
class foo
{
* * function do_foo()
* * {
* * * * echo "Doing foo.";
* * }

}

$bar = new foo;
$bar->do_foo();
?>

But what does it do?

The code that triggered this search was this code:

* * function __construct()
* * {
* * * * $this->soap_client = new SoapClient($this->wsdl);
* * }

In the above, is the $this equivalent to "this" in other languages,
ie. an instance of the object itself? Again, a search of the manual at
php.net did not yield anything for the $this variable.

Thanks.

The part of the manual you must've missed is at:
http://us2.php.net/manual/en/language.oop5.php

$this is explained there in detail, and -by means of many clear
examples. Indeed, $this is like "this" in many other languages. -is
also like -in e.g. c++, and does the same as the dot in e.g. java,
python and ruby. The reason it isn't simply the dot in PHP is probably
because the dot also means string concatenation.

-egbert

[MikeB]

On Jun 1, 11:15 am, Egbert Teeselink <[e-mail]:

On Jun 1, 5:45 pm, MikeB <[e-mail]:

I'm looking at some code and found the -operator. In looking at the
PHP manual at php.net, I can't find a description of what it does. I
can find an example of where it is used, like on this page:http://us2.php.net/manual/en/language.types.object.php

In the sample code like this:

<?php
class foo
{
function do_foo()
{
echo "Doing foo.";
}

}

$bar = new foo;
$bar->do_foo();
?>

But what does it do?

The code that triggered this search was this code:

function __construct()
{
$this->soap_client = new SoapClient($this->wsdl);
}

In the above, is the $this equivalent to "this" in other languages,
ie. an instance of the object itself? Again, a search of the manual at
php.net did not yield anything for the $this variable.

Thanks.

The part of the manual you must've missed is at:http://us2.php.net/manual/en/language.oop5.php

$this is explained there in detail, and -by means of many clear
examples. Indeed, $this is like "this" in many other languages. -is
also like -in e.g. c++, and does the same as the dot in e.g. java,
python and ruby. The reason it isn't simply the dot in PHP is probably
because the dot also means string concatenation.

-egbert

You're right, I did miss that part. I've now read it, and the
preceding PHP 4 Object section.

I was still confused, so then I found this site:
http://www.sitepoint.com/article/object-oriented-php

After reading that I started getting some clarification, but I'm still
a little lost. Now my confusion extends to the double-colon and the
arrow operator.

If I have a class myClass with methods foo and bar

class MyClass{
function foo() {}
function bar() {}
}

then can I write

$thisVariable = myClass::foo /*static call */

and

$classInstance = new MyClass;
$classInstance->foo /* call the foo method in my instance? */

Am I at least on the right track? If there is a good book, about now
I'd be really glad to get a recommendation.

Thanks

[Erwin Moller]

MikeB schreef:

On Jun 1, 11:15 am, Egbert Teeselink <[e-mail]:

>On Jun 1, 5:45 pm, MikeB <[e-mail]:

>>I'm looking at some code and found the -operator. In looking at the
PHP manual at php.net, I can't find a description of what it does. I
can find an example of where it is used, like on this page:http://us2.php.net/manual/en/language.types.object.php
In the sample code like this:
<?php
class foo
{
function do_foo()
{
echo "Doing foo.";
}
}
$bar = new foo;
$bar->do_foo();
?>
But what does it do?
The code that triggered this search was this code:
function __construct()
{
$this->soap_client = new SoapClient($this->wsdl);
}
In the above, is the $this equivalent to "this" in other languages,
ie. an instance of the object itself? Again, a search of the manual at
php.net did not yield anything for the $this variable.
Thanks.

The part of the manual you must've missed is at:http://us2.php.net/manual/en/language.oop5.php

$this is explained there in detail, and -by means of many clear
examples. Indeed, $this is like "this" in many other languages. -is
also like -in e.g. c++, and does the same as the dot in e.g. java,
python and ruby. The reason it isn't simply the dot in PHP is probably
because the dot also means string concatenation.

-egbert

You're right, I did miss that part. I've now read it, and the
preceding PHP 4 Object section.

I was still confused, so then I found this site:
http://www.sitepoint.com/article/object-oriented-php

After reading that I started getting some clarification, but I'm still
a little lost. Now my confusion extends to the double-colon and the
arrow operator.

If I have a class myClass with methods foo and bar

class MyClass{
function foo() {}
function bar() {}
}

then can I write

$thisVariable = myClass::foo /*static call */

and

$classInstance = new MyClass;
$classInstance->foo /* call the foo method in my instance? */

Am I at least on the right track? If there is a good book, about now
I'd be really glad to get a recommendation.

Thanks

Hi,

You can call a classmethod without instantiating the class first.
In that case we say it is a static call to that method (function).

That can be useful to the programmer to pack some functionality in a class.
For example, if you have a bunch of functions that manipulate strings in
some useful way, you can pack them together in a class; to organize your
code.

If you use $this-you must have an instantiated class, since the $this
points to that instantiation.

Regards,
Erwin Moller

[=?ISO-8859-15?Q?Iv=E1n_S=E1nchez_Ortega?=]

MikeB wrote:
[...]

After reading that I started getting some clarification, but I'm still
a little lost. Now my confusion extends to the double-colon and the
arrow operator.

[...]

Am I at least on the right track?

Yes, you're on the right track.

-is the object resolution operator. It applies to instances of objects.

:: is the namespace resolution operator. It applies to classes: static stuff
when you're outside a class, and the very class and its parents when you're
inside of a class. In PHP6, it'll be used to refer to namespaces too.

If there is a good book, about now

Do read the PHP manual.

--
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Iván Sánchez Ortega -ivansanchez-algarroba-escomposlinux-punto-org-

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