Re: Scope of Variables and use of global and this->var
| From: | Darren Karstens | Date: | Tue, 14 Jul 2009 13:01:10 +0000 |
| Subject: | Re: Scope of Variables and use of global and this->var | ||
| References: | 1 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-295362@lists.php.net to get a copy of this message | ||
> Oh and if one class uses methods in another class .... do I instansiate a
> new object of the other class .... I have seen use of OtherClass::Method
> .... is this better method of $obj = new OtherClass() use
The :: is used to access static methods of a class. Static methods can
be used without creating an instance of the class because they dont
use any of the classes member variables.
For example say you have a class with a function for calculating the
area of a rectangle:
class SomeMathFunctions {
public function calculateRectangle($width, $height) {
return $width*$height;
}
}
To use this function you would need to first create an instance of the
class then call the method using the normal -> :
$funcs = new SomeMathFunctions();
$area = $funcs->calculateRectange(10,15);
But if you create the function as static by using " public static
function calculateRectangle($width, $height) { "
then you can access the method by using just 1 call:
$area = SomeMathFunctions::calculateRectange(10,15);
So for creating utility functions its better to use static methods
since you dont get the overhead of creating a new instance of the
class.