Top 50 Common PHP Interview Questions and Answers in 2019
Are you going to interview PHP developer, or preparing for PHP Interview Questions? This guide would help you How to crack a PHP developer interview?
Right, If you are preparing or learning about PHP Interview Questions, then this post worth reading for you. Our PHP developer’s team has prepared a great list of beginner’s level frequently PHP Interview Questions.
PHP has still dominated the world of web development. In today’s, web world PHP still plays a major role in the development of medium to enterprise level web applications. Even the PHP based frameworks like WordPress, Laravel, etc are growing rapidly. So, most of the IT companies are continuously looking for PHP developers and asking PHP Interview Questions for Freshers.
All the PHP Interview Questions are organized as – Question -> Answer -> Example code.
First 15 questions are prepared for php interview questions for freshers
Beginner/Fresher Level PHP Interview Questions and Answers:
Q1). What does PHP stand for? [PHP Interview Questions for Freshers]
PHP stands for – PHP: Hypertext Preprocessor. Sometimes we are confused with its full form.
Here, the PHP developers used recursive acronym which means the first word of the acronym is the acronym(i.e PHP: Hypertext Preprocessor).
Learn more about Recursive Acronym here.
PHP was originally named as Personal Home Page.
Q2). What is PHP and its future? [PHP Interview Questions for Freshers]
PHP is the web engine behind millions of dynamic web applications running in the internet market.
PHP is a server-side web scripting language used to create static or dynamic web pages.
Not, single web page, PHP is used to develop complete static or dynamic simple websites or enterprise level web applications. PHP Interview Questions for Freshers
Most popular examples of recent PHP developments include – PHP based frameworks (Laravel, WordPress, Magento) and CMS (WordPress, Joomla, etc).
Even PHP code can be used outside web pages.
The PHP code is processed by a PHP interpreter that is implemented as an interpreter module in a web server or as a Common Gateway Interface (CGI) executable.
The future of PHP is very bright as it’s used for several programming tasks which include – Desktop GUI applications, Robotic applications and much more…
PHP Interview Questions and Answers
If you are a beginner to Laravel Framework, then we recommend you to read the following topics:
- Laravel Framework Overview
- Laravel Request Lifecycle
- Top 20 Laravel Artisan Commands
- Understanding Laravel Middleware
- Laravel Routing Tutorial
- Understanding Laravel Blade Template
- Laravel Interview Questions
- Laravel Authentication
- Laravel Validation Tutorial
Q3). History of PHP? Who invented PHP? [PHP Interview Questions for Freshers]
PHP was originally developed by Rasmus Lerdorf in 1994.
Q4). How web request/response works in PHP?
[PHP Interview Questions for Freshers]
Each step in the request and response sequence is as follows:
Step1. You enter http://server.com into your browser’s address bar.
Step2. Your browser looks up the IP address for server.com.
Step3. Your browser issues a request for the home page at server.com.
Step4. The request crosses the Internet and arrives at the server.com web server.
Step5. The web server, having received the request, looks for the web page on its disk.
Step6. The web page is retrieved by the server and returned to the browser.
Step7. Your browser displays the web page.
Q5). What is the latest version of PHP? [PHP Interview Questions for Freshers]
The latest version of PHP is 7.2.15 released on 7th March 2019.
To have a complete list of PHP available version access this PHP official page.
Q6). How to check the PHP version from command-line and programmatically in the PHP script?
If you have PHP installed on your local system and PHP bin path added to the $PATH environment variable, like in may case We have added “C:\Bitnami\wampstack-7.1.26-0\php” to my system $PATH.
Then, on Windows OS open the command prompt and run the following to check installed PHP version:
Q7). Is PHP a Low, Medium or High-Level Programming Language?
PHP was originally developed to create web applications. But, with recent advancements in the language, you can also develop GUI based desktop applications in PHP. Even, we can write a PHP program called PHP scripts to run on the console. So, PHP is a high-level language.
Q8). What are the ways in which PHP code can be executed?
PHP is not only used to develop websites. PHP code can be used in multiple ways to achieve different tasks:
[PHP Interview Questions for Freshers]
PHP code i.e .php script can be executed from the CLI (Command Line Interface).
2. Embedded into HTML code
When creating web applications, PHP code can be embedded into plain HTML code.
3. PHP code in Frameworks and CMS’s
Most popular web frameworks are designed and developed using PHP programming language.
Example include Laravel, WordPress, Magento, etc.
Q9). What is the basic structure of PHP Program or Script?
PHP is also known as an embedded scripting language. This means that when developing web pages, PHP code is embedded into the HTML tags. The PHP code is enclosed into the HTML tags like other HTML tags.
NOTE – Note that PHP code is executed on the web server, and the plain HTML result is sent back to the browser.
[PHP Interview Questions for Freshers]
A basic structure of the PHP program:
// PHP code goes here
As shown above, PHP code is enclosed in PHP opening tag (<?php) and closing tag (?>).
The default extention of PHP script is .php.
Example of PHP code embedded into HTML tags:
<h1>My first PHP Script</h1>
echo “Welcome to TechCluesBlog!”;
This simple PHP script would display the output “Welcome to TechCluesBlog” on the web page.
If you open this sample.php in the local browser, the following output would be displayed:
My First PHP Script
Welcome to TechCluesBlog
Let’s understand How PHP script is processed under the hood?
- Step1 – PHP interpreter processes the PHP code enclosed between the <?php and ?> tags.
- Step2 – Once the PHP section is processed, the PHP code is removed from the .php file which is also containing HTML code
- Step3 – If PHP code produces any output, then PHP code is replaced with the output.
- Step4 – Web server returns the plain HTML code back to the web browser
- Step5 – Finally, the web browser process only HTML tags and render the HTML view on the web page.
Q11). What are the applications of PHP programming language?
[PHP Interview Questions for Freshers]
PHP has dominated the world of modern web as well as standalone applications.
But, it is widely used for web applications.
Important Applications of PHP:
1. Static and Dynamic Websites
2. Medium to Large scale Web applications.
3. CMS Development
4. Development of E-Commerce platforms and applications
Examples are – OpenCart, Magento, PrestaShop, Zen Cart, AgoraCart and Ubercart, have all been created on PHP.
5. GUI-Based Desktop Applications
Tools like PHP-GTK 2, DevelStudio and ZZEE PHP GUI, allow scripting in PHP code and compiling it into an executable (i.e .exe) capable of running as a standalone application.
6. Image Processing and Graphic Design
7. Data Gathering and Data Representation
8. PDF Invoicing:
Q12). What a PEAR in PHP language? [PHP Interview Questions for Freshers]
PEAR is the PHP Extension and Application Repository. PEAR is a collection of open source packages i.e classes that work together to achieve a particular functionality.
For example, PHP Developers can use PEAR classes to parse XML, implement authentication systems, generate CAPTCHAs, send MIME mail with attachments, and a wide variety of other common (and not so common) tasks.
PEAR was initially founded by Stig S. Bakken under PEAR project in 1999 to promote the re-use of PHP code that performs common functions.
Q13). What is PECL and what PECL stands for? [PHP Interview Questions for Freshers]
PECL is the PHP Extension Community Library. PECL, pronounced “pickle,” is a series
of extensions to PHP developed in C.
Q14). Which scripting engines does PHP use under the hood?
PHP scripting language uses the Zend Engine.
Q15. What is Zend Engine? [PHP Interview Questions for Freshers]
The Zend Engine – is the heart of the PHP that parses, processes understands and executes all of your PHP scripts(.php file) at the server side. Zend is the open source engine that interprets the PHP code. It was developed by Andi Gutmans and Zeev Suraski who later formed Zend Technologies in Israel.
Zend works like OS (Operating System) for PHP programming language.
The magic behind the name Zend is – a combination of their forenames, Zeev and Andi.
Zend Engine is responsible for the following tasks:
- Zend works as of PHP interpreter that analyzes the input code, translates it, and executes it.
- High-performance parsing (including syntax checking), in-memory compilation and execution of PHP scripts
- Provides Implementation of all of the standard PHP functions and data structures.
- Providing all of the standard services, including memory management, resource management and more for the whole of PHP
Q16). List some popular PHP based frameworks and PHP CMS’s?
Below is the list of most popular PHP based CMS’s (Content Management Systems):
CMS Made Simple
Below is the list of most popular PHP based web development frameworks:
Q17). How to declare and initialize a variable in PHP?
A variable is a container to store some value – a character, an integer or string, etc. Declaring and Initializing a variable primary task in any programming language. It is very simple to define and use a variable in PHP.
In PHP variables are declared, initialized, and accessed using the $ sign followed by the name of the variable:
PHP Variables Example
For example, to store the salary of an employee we will use the following code:
$emp_salary = 100000
Here, the “emp_salary” is a variable name assigned with the value of 100000.
PHP Variable Example code
$emp_name = “Mr. Tejinder”;
$emp_salary = 100000;
$emp_age = 34;
Note: Note that unlike other programming languages like C or C++, variable in PHP are created at the moment they are first assigned some value.
Q18). Explain the difference between echo and print functions in PHP?
Answer: PHP Interview Questions for Freshers
The PHP echo and print statements are more or less the same, both are used to print output to the screen.
There is a minor difference between PHP echo and print statements. Following are the main differences:
1. The echo has no return value whereas print has a return value of 1.
2. Echo can have multiple arguments separated by commas while print can have only one argument.
3. PHP Echo is a bit faster than the PHP print statement.
PHP Echo example – PHP Interview Questions for Freshers
echo “<h2>PHP echo example</h2>”;
echo “Hello PHP echo<br>”;
echo “This “, “string “, “was “, “made “, “with multiple parameters.”;
$age = 35;
echo “Age = ” . $age . “<br>”;
PHP print example – PHP Interview Questions for Freshers
print “<h2>PHP print example</h2>”;
print “Hello PHP print<br>”;
$name = “TechCluesBlog”;
print “Name is : ” . $name . “<br>”;
Note – The PHP print statement can be used with or without parentheses: print or print().
Q19). What is the default extension of the PHP script file and how to execute PHP script from command-line?
The default extension of PHP script files is .php. These pure PHP scripts can also be executed from the command line. To execute a PHP script from the command line, use the php command followed by the name of the script file. PHP Interview Questions
For example, to execute sample.php run the following command:
Q20). What is an array in PHP and how to create arrays in PHP?
In PHP, an array is an organized group of related values stored in the single in a variable. Arrays in PHP are like a list in other languages. PHP arrays are used to store similar types of items into a single unit. PHP Interview Questions
For example, the names of all students can be stored in the student array.
PHP supports the following types of arrays:
– PHP numeric arrays
– PHP associative arrays
– PHP Multi-Dimentional Arrays.
PHP array() function is used to create an array in PHP:
$cities = array(“Volvo”, “BMW”, “Toyota”);
PHP array example
$cars = array(“Volvo”, “BMW”, “Toyota”);
echo “I like ” . $cars . “, ” . $cars . ” and ” . $cars . “.”;
This guide can also be helpful to prepare PHP Interview Questions for Freshers and experiennced developers.
Summary – Best PHP Interview Questions with Answers
We hope that you have enjoyed this guide and it would help you crack the PHP interview or at least improved your basic knowledge of PHP. In this post, we have put our sincere efforts to cover fundamental concepts of PHP programming language.
We will continue updating this post with the new set of PHP Interview Questions.
Hope you have enjoyed our list of PHP Interview Questions!