PHP Magic Methods
The function names __construct(), __destruct(), __call(), __callStatic(), __get(), __set(), __isset(), __unset(), __sleep(), __wakeup(), __toString(), __invoke(), __set_state(), __clone() and __debugInfo() are magical in PHP classes. You cannot have functions with these names in any of your classes unless you want the magic functionality associated with them. Caution PHP reserves all function names starting with __ as magical. It is recommended that you do not use function names with __ in PHP unless you want some documented magic functionality.
__toString()
<?php
class Test
{
public $name;
public function __construct($name)
{
$this->name= $name;
}
}
$obj = new Test('Tim');
echo $obj;
?> __set_state()
<?php
class Test
{
private $value1;
private $value2;
public function __construct()
{
$this->value1 = 100;
$this->value2 = "name";
}
public static function __set_state(array $array) {
$tmp = new Test();
$tmp->value1 = $array['value1'];
$tmp->value2 = "my ".$array['value2'];
return $tmp;
}
}
$testObj = new Test();
$strCode = var_export($testObj, true);
eval($strCode.';');
?>__invoke()
<?php
class test
{
public function __invoke()
{
echo "I can act as a function now.....";
}
}
$obj = new test;
$obj();
var_dump(is_callable($obj));
?>__debugInfo()
<?php
class Student
{
private $id;
public $name;
public function __construct( $id, $name)
{
$this->id = $id;
$this->name = $name;
}
public function __debugInfo() {
return [
'Student Id' => $this->id * 2,
'Address'=> 'abc'
];
}
}
$stuObj = new Student( 2, "name");
var_dump($stuObj);
?>__sleep()
<?php
Class Student{
public $name;
public $id;
public $address;
public $age;
public function printStudentInfo(){
echo "Student name = ".$this->name."</br>";
echo "Student id = ".$this->id."</br>";
}
public function __sleep() {
//(Clean up; close database handles, etc)
return array( "id", "address" );
}
}
?><?php
// page1.php:
include("Student1.php");
$stuObj = new Student;
$stuObj->name= "Tim";
$stuObj->id = 10;
$stuObj->address= "abc";
$stuObj->age = 20;
$s = serialize($stuObj);
echo $s;
// store $s somewhere where page2.php can find it.
file_put_contents('store.txt', $s);
?>__wakeup()
<?php
Class Student{
public $name;
public $id;
public $address;
public $age;
public function printStudentInfo(){
echo "Student name = ".$this->name."</br>";
echo "Student id = ".$this->id."</br>";
}
public function __sleep() {
return array_keys( get_object_vars( $this ) );
}
public function __wakeup() {
echo "Hello guys i m back from hibernation....</br>";
}
}
?><?php
// page2.php:
// this is needed for the unserialize to work properly.
include("Student3.php");
$s = file_get_contents('store.txt');
$stuObj = unserialize($s);
// now use the function printStudentInfo() of the $stuObj object.
$stuObj->printStudentInfo();
?>__clone()
<?php
class Charger{
public $name;
public function __construct($name){
$this->name = $name;
}
public function charging(){
echo "Charger name ".$this->name." Charging........";
}
}
Class ToyCar{
public $carName;
Public $colour;
Public $chargerObj;
public function __clone(){
$this->chargerObj = clone $this->chargerObj;
}
public function __construct($name, $colour, $charger){
$this->carName = $name;
$this->colour = $colour;
$this->chargerObj = $charger;
}
}
$charObj = new Charger("6 Volt Charger.");
$carObj = new ToyCar("Car 1", "Black", $charObj);
$otherCarObj = clone $carObj;
$otherCarObj->carName = "Car2";
$otherCarObj->chargerObj->name = "12 Volt Charger";
print_r($carObj);
echo "</br></br>";
print_r($otherCarObj);
?>__set()
<?php
class Student
{
public function __set( $propertyName, $propertyValue )
{
echo"Property name is $propertyName and its value is $propertyValue";
}
}
$stuObj = new Student();
$stuObj->grade = "Good Grades";
?>__get()
<?php
class Student
{
public function __set( $propertyName, $propertyValue )
{
echo"Property name is $propertyName and its value is $propertyValue";
}
public function __get( $propertyName )
{
return "Tim";
}
}
$stuObj = new Student();
echo $stuObj->studenName;
?>__isset() and __unset()
<?php
class Student{
private $_extraInfo = array();
public function __set($propertyName,$propertyValue){
$this->_extraInfo[$propertyName] = $propertyValue;
}
public function __get($propertyName){
if ( array_key_exists( $propertyName, $this->_extraInfo ) ) {
return $this->_extraInfo[$propertyName];
} else {
return null;
}
}
public function __isset($propertyName){
if(isset($this->_extraInfo[$propertyName])){
echo "Property \$$propertyName is set.<br/>";
} else {
echo "Property \$$propertyName is not set.<br/>";
}
}
public function __unset($propertyName){
unset($this->_extraInfo[$propertyName]);
echo "\$$propertyName is unset <br/>";
}
}
$objStudent = new Student();
$objStudent->birthCountry = "Germany";
$objStudent->nationality = "United Kingdom";
echo "Overloaded Property name is \$birthCountry= ";
echo $objStudent->birthCountry . "</br>";
echo "Overloaded Property name is \$nationality= ";
echo $objStudent->nationality . "</br></br>";
isset($objStudent->birthCountry);
isset($objStudent->nationality);
echo "</br>";
unset($objStudent->birthCountry);
unset($objStudent->nationality);
echo "</br>";
isset($objStudent->birthCountry);
isset($objStudent->nationality);
?>__call() and __callStatic()
<?php
class Test
{
public function __call($methodName, $arguments)
{
echo "Calling object method '$methodName' with Arguments("
. implode(', ', $arguments). ")</br></br>";
}
public static function __callStatic($methodName, $arguments)
{
echo "Static method $methodName is called.";
if($methodName == "multiply"){
$total = 1;
foreach($arguments as $num){
$total = $total * $num;
}
echo " answer is = $total";
}else{
echo " I am not doing anything Hun!!!.";
}
}
}
$obj = new Test;
$obj->runTest(1,2);
Test::Multiply(2, 4, 3, 4, 5);
?>