note 113914 added to language.oop5.basic
| From: | sklemnov at gmail dot com | Date: | Tue, 17 Dec 2013 00:44:52 +0000 |
| Subject: | note 113914 added to language.oop5.basic | ||
| Groups: | php.notes | ||
| Request: | Send a blank email to php-notes+get-197956@lists.php.net to get a copy of this message | ||
Small subtlety to anyone just starting out: using $this is for referencing an instance of the
current class (there are exceptions to this, but on the basic level it is mostly true; please do not
downvote this, it's not meant to be a PhD dissertation).
For instance,
class TestClass{
private $variable = "Hello";
function ReturnVar(){
return $this->variable;
}
function SetVar($input){
$this->variable = $input;
}
}
$t = new TestClass();
echo $t->ReturnVar();
$t->SetVar("Test");
echo $t->ReturnVar();
This is a useless piece of code that illustrates $this in functions.
echo $t->ReturnVar();
outputs "Hello", and then:
$t->SetVar("Test");
sets the object $t's copy of $variable to "Test". Finally,
echo $t->ReturnVar();
returns the new value of $t's copy of $variable, namely "Test".
using $this in the ReturnVar() function tells PHP that you want to return $t's copy of
$variable.
Suppose we took $this out of the above code:
class TestClass{
private $variable = "Hello";
function ReturnVar(){
return $variable;
}
function SetVar($input){
$variable= $input;
}
}
$t = new TestClass();
echo $t->ReturnVar();
$t->SetVar("Test");
echo $t->ReturnVar();
Would show nothing at all! PHP would not know that you meant to reference object $t's version
of $variable.
----
Server IP: 72.52.91.14
Probable Submitter: 72.52.91.14
----
Manual Page -- http://php.net/manual/en/language.oop5.basic.php
Edit -- https://master.php.net/note/edit/113914
Del: integrated -- https://master.php.net/note/delete/113914/integrated
Del: useless -- https://master.php.net/note/delete/113914/useless
Del: bad code -- https://master.php.net/note/delete/113914/bad+code
Del: spam -- https://master.php.net/note/delete/113914/spam
Del: non-english -- https://master.php.net/note/delete/113914/non-english
Del: in docs -- https://master.php.net/note/delete/113914/in+docs
Del: other reasons-- https://master.php.net/note/delete/113914
Reject -- https://master.php.net/note/reject/113914
Search -- https://master.php.net/manage/user-notes.php