What are magic methods and how to use them in PHP ?

 PHP magic methods are special methods that are called automatically when certain conditions are met. There are several magic methods in  PHP. Every magic method follows certain rules -

• Every magic method starts with a double underscore (  __ ).
• They are predefined and neither can be created nor removed.
• Magic methods have reserved names and their name should not be used for other purposes.
• Magic methods are automatically called when certain criteria are met.

The following are code snippets and examples to understand magic methods better.

__construct() Method: In the below example, the MagicMethod class has a magic method __construct() and it is called every time when a new object of MagicMethod class is created.

<?php
  
class MagicMethod {
    function __construct() {
        echo "This is the construct magic method";
    }
}

// Creating object of Magic method class
$obj = new MagicMethod();
   
?>

This is the construct magic method

__destruct() Method: In the below example, the MagicMethod class has a magic method __destruct() that gets called automatically when the object of MagicMethod destroys. 

<?php

class MagicMethod {
    function __destruct() {
        echo "This destruct magic method "
        + "gets called when object destroys";
    }
}

$obj = new MagicMethod();

?>

This destruct magic method gets called 
when object destroys

__call($name, $parameters) Method: This method gets called when a method or property is called which has not been defined.

This method takes two parameters:

• $name: This contains the name of the method which was called.
• $parameters: This is an array of parameters that were given to that method.

<?php

class MagicMethod {
    function __call($name , $parameters){
        echo "Name of method =>" . $name."\n";
        echo "Parameters provided\n";
        print_r($parameters);
    }
}

// Instantiating MagicMethod
$obj = new MagicMethod();

$obj->hello("Magic" , "Method");

?>

Name of method =>hello
Parameters provided
Array
(
    [0] => Magic
    [1] => Method
)

__toString() Method: This method gets called when an object is treated as a string. This method is also useful to represent an object as a String.

<?php

class MagicMethod {
    function __toString(){
        return "You are using MagicMethod object as a String ";
    }
}

$obj = new MagicMethod();

echo $obj;

?>

You are using MagicMethod object as a String 

__get($name) Method: This method gets called when an inaccessible (private or protected  ) variable or non-existing variables are used.

<?php

class MagicMethod {
    function __get($name){
        echo "You are trying to get '" . $name . 
          "' which is either inaccessible 
           or non existing member"; 
    }
}

$obj = new MagicMethod();
$obj->value;

?>

You are trying to get 'value' which is either 
inaccessible or non existing member

__set($name, $value) Method: This method is called when an inaccessible variable or non-existing variable is tried to modify or alter.

<?php

class MagicMethod {
    function __set($name , $value) {
        echo "You are trying to modify '" 
          . $name . "' with '" . $value . 
          "' which is either inaccessible 
          or non-existing member";
    }
}
$obj = new MagicMethod();
$obj->value = "Hello";

?>

You are trying to modify 'value' with 'Hello' which is either inaccessible 
          or non-existing member

__debugInfo() Method: This method is used when the var_dump() function is called with object as a parameter. This method should return an array containing all the variables which may be useful in debugging.

<?php

class MagicMethod {
    function __debugInfo(){
        return array("variable"=> "value");
    }
}

$obj = new MagicMethod();
var_dump($obj);

?>

object(MagicMethod)#1 (1) {
  ["variable"]=>
  string(5) "value"
}