Geek Answer

In simple words 'object cloning' can be defined as copying the object property and assigning to a different object. But when we copy an object then it only owns the reference, not the value. In PHP this is done by two method- 1) By using clone Keyword- In this, a shallow copy of the object is made. It means the internal object of the objectA is not cloned to the internal object of objectB. class CloneableClass { private $_internalObject ; public function __construct () { // instantiate the internal member $this -> _internalObject = new stdClass (); } } $objectA = new CloneableClass (); $objectB = clone $objectA ; 2) By using __clone() method- if your object holds a reference to another object which it uses and when you replicate the parent object you want to create a new instance of this other object so that the replica has its own separate copy. In this the magic method __clone() is

The working of Index in database tables is the same as index work in a Text Book . It will help to browse the desired content faster in a book. we use to see the index on the first page then we check the page where it is in the book and then we directly come to that page, instead of going through all pages. Now databases , same happen with tables, if you are applying select query on the table, it will also check for the index and then return you the required field. It will return the field faster on which index is applied. Or in language, we can say that the index one query will execute faster instead of the non-indexed one. Join will execute faster on indexed one. eg- Consider a Table Product with `id` as Primary Key  id name price category_id  location_id                Table Info- Now  Applying Index on category_id  SELECT category_id FROM product WHERE category_id='5'; SELECT category_id FROM product WHERE location_id='10'; Firs

There are many magic methods in PHP like  __construct(), __destruct(), __callback(), __get(), __set(), __sleep(), __wake() and many more. But we will be takingon  on  __sleep() and  __wake(). __sleep() : serialize() checks if your class has a function with the magic name __sleep(). If so, that function is executed prior to any serialization. It can clean up the object and is supposed to return an array with the names of all variables of that object that should be serialized. If the method doesn't return anything then NULL is serialized and E_NOTICE is issued. serialize() is used for the representation of the storage class for storing the value. Serializing   an object means converting it to a byte stream representation that can be stored in a file. The use of __sleep()  to commit the pending task. If a bulk data is being inserted then at that time __sleep can be used. it will not release the object unless the work is not completed. Or if a table is being altered and