Encapsulation is the packing of data and functions into a single component. The features of encapsulation are supported using classes in most object-oriented programming languages, although other alternatives also exist.
$result = mysql_fetch_assoc(mysql_query(“SELECT * FROM `topics` WHERE tid='”.$topic_id.”‘”));
echo return $result[‘posts’] ;
<?php echo get_author_posts_url(get_the_author_ID()) ?>
PHP 5 introduces abstract classes and methods. Classes defined as abstract may not be instantiated, and any class that contains at least one abstract method must also be abstract. Methods defined as abstract simply declare the method’s signature – they cannot define the implementation.
When inheriting from an abstract class, all methods marked abstract in the parent’s class declaration must be defined by the child; additionally, these methods must be defined with the same (or a less restricted) visibility. For example, if the abstract method is defined as protected, the function implementation must be defined as either protected or public, but not private. Furthermore the signatures of the methods must match, i.e. the type hints and the number of required arguments must be the same. For example, if the child class defines an optional argument, where the abstract method’s signature does not, there is no conflict in the signature.
A destructor is a method which is automatically invoked when the object is destroyed.
Its main purpose is to free the resources
A is special method of the class that will be automatically invoked when an instance of the class is created is called as constructor.
Constructors are mainly used to initialize private fields of the class while creating an instance for the class.
When you are not creating a constructor in the class, then compiler will automatically create a default constructor in the class that initializes all numeric fields in the class to zero and all string and object fields to null.
Types of Constructors
- Default Constructor
- Parameterized Constructor
- Copy Constructor
- Static Constructor
- Private Constructor
mysql Ver 14.14 Distrib 5.1.61, for debian-linux-gnu (i686) using readline 6.1
There is no difference
1) For abstract class a method must be declared as abstract. Abstract methods doesn’t have any implementation.
For interface all the methods by default are abstract methods only. So one cannot declare variables or concrete methods in interfaces.
2) The Abstract methods can declare with Access modifiers like public, internal, protected. When implementing in subclass these methods must be defined with the same (or a less restricted) visibility.
All methods declared in an interface must be public.
3)Abstract class can contain variables and concrete methods.Interfaces cannot contain variables and concrete methods except constants.
4)A class can Inherit only one Abstract class and Multiple inheritance is not possible for Abstract class.
A class can implement many interfaces and Multiple interface inheritance is possible.