Introduction to PHP Abstract Classes
The abstraction is a process in which the programmer hides the unnecessary data and only shows the data that is in the context of the end user. This reduces the complexity of the program and makes it easier to use.The abstract classes and methods have been introduced in PHP5. Abstract classes and methods are used to implement an abstract oriented programming abstraction feature.
Abstract methods
Abstract methods are those methods.
1.Those who do not have a method body.
2.Whose names and parameters are declared.
3.Which are declared with abstract keyword.
Abstract methods are only defined in abstract classes. Their body provides the class which inherits the abstract class.
Abstract Classes
Abstract is class which contains one or more abstract methods and is defined by abstract keyword.
Some important charcterstics are given below of the abstract classes which make them different from the other classes.
1.If a class has one or more abstract method then it is mandatory that the class is also abstract.
2.Apart from abstract methods in an abstract class, common properties and methods can also be declared.
3.Abstracts class which inherits class and signature methods of abstract class must match perfectly.
Important Notes :-
One thing you should always keep in mind is that abstract class does not support multiple inheritance. Although an abstract class can inherit another abstract class, but the normal class inheriting the abstract class should not be inherited by a second class.
Abstract Classes Syntex
abstract class MyAbstract { //Methods } //And is attached to a class using the extends keyword. class Myclass extends MyAbstract { //class methods }
Example
<?php abstract class a { abstract public function dis1(); abstract public function dis2(); } class b extends a { public function dis1() { echo "expertsphp"; } public function dis2() { echo "GOOD"; } } $obj = new b(); $obj->dis1(); $obj->dis2(); ?>