Magic Methods in PHP

• All magic methods MUST be declared as public.
• It is recommended that you do not use function names with __ in PHP unless you want some documented magic functionality.

PHP Magic Methods	Functionality
_construct	This magic methods is called when someone create object of your class. Usually this is used for creating constructor in php5.
__destruct	This magic method is called when object of your class is unset. This is just opposite of __construct.
__get	__get() is utilized for reading data from inaccessible properties.
__set	__set() is run when writing data to inaccessible properties.
__isset	This magic methods trigger when isset() function is applied on any property of the class which isinaccessible or unavailable.
__unset	__unset is something opposite of isset method. This method triggers when unset() function called on inaccessible or unavailable property of the class.
__call	__call magic method trigger when you are attempting to call method or function of the class which is either inaccessible or unavailable.
__callstatic	__callstatic execture when inaccessible or unavailable method is in static context.
__sleep	__sleep methods trigger when you are going to serialize your class object.
__wakeup	__wakeup executes when you are un serializing any class object.
__toString	__toString executes when you are using echo on your object.
__invoke	__invoke called when you are using object of your class as function

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__construct method trigger on the creation of an object, and __destruct triggers on deletion of an object.

Following is very basic example of __construct and __destruct magic method in php:

__get, __set, __call and __callStatic all magic methods in php directly related with no accessible method and property of the class.

__get takes one argument and executes when any inaccessible property of the method is called. It takes name of the property as argument.

__set takes two property and executes when object try to set value in inaccessible property. It take first parameter as name of the property and second as the value which object is try to set.

__call() is triggered when invoking inaccessible methods in an object context. It takes 2 parameter First parameter is string and is name of function. Second parameter is an array which is arguments passed in the function.

__callStatic() is triggered when invoking inaccessible methods in a static context.

Syntax:

public mixed __call ( string $name , array $arguments )
public static mixed __callStatic ( string $name , array $arguments )

class MethodTest
{
    public function __call($name, $arguments)
    {
        // Note: value of $name is case sensitive.
        echo "Calling object method '$name' " . implode(', ', $arguments). "\n";
    }
    /** As of PHP 5.3.0 */
    public static function __callStatic($name, $arguments)
    {
        // Note: value of $name is case sensitive.
        echo "Calling static method '$name' " . implode(', ', $arguments). "\n";
    }
}
$obj = new MethodTest;
echo $obj->runTest('in object context');
echo MethodTest::runTest('in static context'); // As of PHP 5.3.0

//Output: 
Calling object method 'runTest' in object context
Calling static method 'runTest' in static context

1. __isset and __unset magic methods in PHP are opposite of each other.
2. __isset magic methods execute when function isset() is applied on the property which is not available or not defined. It takes the name of the parameter as an argument.
3. __unset magic method triggers when unset() method is applied to the property which is either not defined or not accessible. It takes the name of the parameter as an argument.

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class test
{
    function __isset($name)
    {
        echo "__isset is called for $name";
    }
    function __unset($name)
    {
        echo "__unset is called for $name";
    }
}
$a = new test(); isset($a->x); unset($a->c);

For more details on Magic Methods visit http://php.net/manual/en/language.oop5.magic.php

class Person{
    function getName(){ return "Ramesh"; }
    function getAge(){ return 24; }
    function __toString(){
        return $this->getName(). "'s age is ". $this->getAge();
    }
}
$person = new Person();
echo $person;

//Output: Ramesh's age is 24