Object-Oriented Programming Concepts in PHP – Interface

Interface

Interfaces are defined in the same way as a class, but with the interface keyword replacing the class keyword and without any of the methods having their contents defined.

All methods declared in an interface must be public; this is the nature of an interface.

Interfaces allow you to create code which specifies which all methods a class must implement.

Note that it is possible to declare a constructor in an interface.

Implements

• To implement an interface, the implements operator is used.
• All methods in the interface must be implemented within a class; failure to do so will result in a fatal error.
• Classes may implement more than one interface if desired by separating each interface with a comma.
• Interfaces can be extended like classes using the extends operator.
• The class implementing the interface must use the exact same method signatures as are defined in the interface. Not doing so will result in a fatal error.

Example:

<?php

// Declare the interface 'myImplement'

interface myImplement

{

public function setVariable($name, $val);

public function getVariable($tempdata);

}

// Implement the interface

class temp implements myImplement

{

private $vars = array();

 // Implementing the SetVatiable  Method

public function setVariable($name, $val)

{

       $this->vars[$name] = $name;

       $this->vars[$val] = $val;

}

 // implementing the GetVariable Method

public function getVariable($tempdata)

   {

       foreach($this->vars as $name => $value) {

        $tempdata = str_replace('{' . $name . '}', $value, $tempdata);

    }

//return the result

    return $tempdata;

}

}

// Instance creation ( object)

$objTemp = new temp();

// set the values to setvariable method

$rest=$objTemp -> setVariable('bala','Welcome');

$rest=$objTemp -> setVariable('balaa','Welcome1');

$rest=$objTemp -> setVariable('bala1','Welcome2');

$rest=$objTemp -> setVariable('bala2','Welcome3');

// get the value from getvariable method

$objTemp -> getVariable($rest);

echo "<pre>";

print_r($objTemp);

?>

OUTPUT:

temp Object
(
   [vars:temp:private] => Array
       (
           [bala] => bala
           [Welcome] => Welcome
           [balaa] => balaa
           [Welcome1] => Welcome1
           [bala1] => bala1
           [Welcome2] => Welcome2
           [bala2] => bala2
           [Welcome3] => Welcome3
       )

)