Hi guys, In this article we are going to understand the concept of static methods and variables. Methods and variables can also be used and accessed if they are defined as static in a class.
Concept
Static means the method or variable is accessible through the class
definition and not just through objects. The ::operator allows you to refer to
variables and methods on a class that doesn't yet have any instances or objects
created for it.
Script for PHP
Using the -> and :: operators to call
hypnotize:
<html>
<body bgcolor="cyan">
<center>
<h3>
Static methods and variables in PHP <h3>
<hr>
<?php
class Cat {
}
class Hypnotic_Cat
extends Cat {
//
Constructor
function Hypnotic_Cat()
{
}
// This
function must be called statically
public static function hypnotize()
{
echo ("The
cat was hypnotized.");
return;
}
}
//
Hypnotize all cats
Hypnotic_Cat::hypnotize();
$hypnotic_cat = new
Hypnotic_Cat();
//
Does nothing
$hypnotic_cat->hypnotize();
?>
</center>
</body>
</html>
Save it as abc.php.
Output
To run the code, Open the XAMPP server and start the services like Apache and
MySQL. Open the browser type: http://localhost/yourfoldername/abc.php
Note :
When a method is called using the
scope resolution operator (::), you can't use the $this object to refer to the
object because there is no object.
Variables in PHP
Here I am going to explain variables in terms of php.
-
A variable name points to a location in memory that stores the data. There can be more than one variable name pointing to the same spot in memory.
-
The ampersand operator (&) is used to indicate that you're interested in the location in memory that a variable points to instead of its value.
-
PHP references allow you to create two variables to refer to the same content. There-fore, changing the value of one variable can change the value of another. This can make it very difficult to find errors in your code, since changing one variable also changes the other.
Syntax
Using a variable $svariable
<html>
<body bgcolor="Orange">
<center>
<h3>
variables in PHP <h3>
<hr>
<?php
$svariable
=
"Hello Friends!";
$sreference = &$some_variable;
$sreference = "This is
DEEPAK DWIJ!";
echo $svariable;
echo $sreference;
?>
</center>
</body>
</html>
Save it as abc.php.
Output
To run the code, Open the XAMPP server and start the services like Apache and
MySQL. Open the browser type: http://localhost/yourfoldername/abc.php
Thanks !