Page 214 - Beginning PHP 5.3

Part II: Learning the Language
To access an object ’ s property from within a method of the same object, you use the special variable
name $this , as follows:
$this-> property;

For example:

class MyClass {

public $greeting = “Hello, World!”;

public function hello() {

echo $this-> greeting;
}
}

$obj = new MyClass;

$obj-> hello(); // Displays “Hello, World!”
In this example, a class, MyClass , is created, with a single property, $greeting , and a method, hello() .
The method uses echo to display the value of the $greeting property accessed via $this - > greeting .

After the class definition, the script creates an object, $obj , from the class, and calls the object ’ s hello()
method to display the greeting.
Note that the $this inside the hello() method refers to the specific object whose hello() method is
being called — in this case, the object stored in $obj . If another object, $obj2 , were to be created from
the same class and its hello() method called, the $this would then refer to $obj2 instead, and
therefore $this - > greeting would refer to the $greeting property of $obj2 .

By the way, you can also use $this to call an object ’ s method from within another method of the
same object:

class MyClass {

public function getGreeting() {
return “Hello, World!”;
}

public function hello() {
echo $this->getGreeting();
}
}

$obj = new MyClass;

$obj-> hello(); // Displays “Hello, World!”
Here, the hello() method uses $this - > getGreeting() to call the getGreeting() method in the

same object, then displays the returned greeting string using echo .

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