class Fruit {
 private $color;

 public function eat() {
  //chew
 }

  public function setColor($c) {
   $this->color = $c;
  }
 }

 class Apple extends Fruit {
  public function eat() {
   //chew until core
  }
 }

 class Orange extends Fruit {
  public function eat() {
   //peel
   //chew
  }
 }

Now taste an apple

$apple = new Apple();
$apple->eat();

What’s the taste of it? Obviously it’s apple

Now eat a fruit

$fruit = new Fruit();
$fruit->eat();

What’s the taste of it? It doesn’t make any sense. does it? Which means the class fruit should not be Instantiable . This is where the abstract class comes into play

abstract class Fruit {
 private $color;

 abstract public function eat()

 public function setColor($c) {
  $this->color = $c;
 }
}

This is just a quick note about how you must prepare for your technical interview whether it’s a face to face or a written.
Before you prepare for a technical interview you must re-work on your basics in the first place. if you are not sure enough don’t go to the interview. Prepare well for your next interview. It will help you a lot 

For an instance at least work on following aspects,

• Client Server  – > What is client server architecture? Basic requesting methods to the server?
• Sessions  -> What is a session? Where sessions are stored? How session reference is carried in the browser(client) side?
• OOP     -> What is a class? what is overloading? what is overriding and how you do these with examples?
• XML    -> What is xml? and what’s the use of it?
• AJAX -> What is ajax? if you use 3rd party tool at least know the basic functions.
• Frameworks – > Design patterns used? MVC? Explain cakephp, zend etc
• CMS-> At least the knowledge of integrating a template. Joomla, Drupal, Magento

Here is a list of php question areas that might be asked in an add-hoc oral technical interview.

First of all they will focus on some more basic questions,
- Difference between GET and POST
- Echo and print
- Language constructors and so on…

Then most likely they would focus on,
- The behaviors of sessions and cookies
- Ways of a session ID can be passed
- Db connection strings and how can it be centralized and stuff like that.
- Difference between normal connection and a persistent connection etc..

Then obviously the interviewer will have to asses on your knowledge in Object Oriented Programming techniques,
- Simply what is a class or object?
- Some definitions on OOP techniques like, Encapsulation, overloading, inheritance.

Also design pattern questions will be asked here.
- Which OOP pattern implements a class that must be instantiated only once in a life span of a script?
- Some more questions on design patterns mostly real world scenarios.
- How design patterns can be used as a mix of more than one pattern?
- Some more discussions related to MVC, Abstract factory, and singleton.

Last but not least they will focus on your knowledge about the security issues, best practices, probably about register global issues and so on. Then the interviewers will focus on more into your CV and about the Frameworks and CMS’s you have been exposed to.

We will be discussing all of above points one by one in later posts stay tuned.

Cheers !

A class is a blueprint of an object, which is an instance of a class.

What will out put the following code snippet?

<?php
$who = "questions";
echo <<<TEXT
So I said, "php interview $who"
TEXT;
?>

Answer – So I said, “php interview questions”

In general, the functionality of this heredoc syntax is similar to double quotes.

“I am visiting the php interview questions website”.
The word “question” is inside a variable,
$a = ‘question’;

Answer is just,
echo “I am visiting the php interview {$a}s website”;

In a php interview, even a well experienced php programmer might forget how this works,
For an example,
a) echo “Hello $what\n”;
b) echo ‘Hello $what\n’;
$what = “World”;

Which will print correctly in to the browser as “Hello World” followed by a new line.
Is it a) or b) ?

The answer is “a”. That is because simple string will print almost all characters literally, where complex string allows special escape sequences to insert special characters.

Frameworks – Zend Framework, cakephp

CMS’s – Drupal, joomla, wordpress

(wordpress is acutally a blog / CMS).

function r(){
//return 1;
}

Here you will not get a chance to execute and see what is the out put.  So you have to know exactly what will happen here. Probably even if you are a php pro, sometimes you might get confused here.
It will print “aaa”, even though the function do not return anything.

- Make register_globals to off to prevent Form Injection with malicious data.

- Set Error_reporting to E_ALL so that all variables will be intialized before using them.

- Practice of using htmlentities(), strip_tags(), utf8_decode() and addslashes()  for filtering malicious data in php

- Make practice of using mysql_escape_string() in mysql.

GET transfer data to the server using URL whereas POST transfer data using form collection which is added to the request by the browser. We can send at most 1024 bytes using URL hence there is upper limit for GET method POST method can transfer large amount of data where upper limit is imposed by web server which is about 2MB data is shown to the user in GET method.

Get is faster but not safe.
http://www.tutorialspoint.com/php/php_get_post.htm

Session is stored in the server side.

header() function.
eg:- header(‘Location:interview_questions.php’)
This must be called before any output is called.

No it is not possible.