100+ PHP Interview Questions And Answers

Use OOP principles and design patterns like factory method pattern, dependency injection and observer pattern to write scalable, modular and testable code. You need to handle exceptions gracefully by logging and displaying errors to users in a user-friendly manner. PHP scripts can generate HTML and transmit data between the two. In PHP, the __get() method is a magic method used for intercepting and handling attempts to read inaccessible or undefined properties within an object. It is automatically called when a property is accessed that is not accessible or does not exist.

PHP developer interview questions

Indexed Array – An indexed array is one that has a numeric index. _CLASS_ – This function returns the name of the class as it was declared. PEAR is a framework and repository for PHP components that can be reused. PHP Extension and Application Repository (PEAR) is an acronym for PHP Extension and Application Repository. It’s full of PHP code snippets and libraries of all kinds. It also has a command-line interface for automatically installing „packages.“

Common Questions Everyone Has When Making Their First Pull Request (& Answers)

In PHP, include and require are used to import code from other PHP files into the current script. The common applications of using them are modularity and code reusability. Include allows the script to continue running even if the included file is missing or fails to load, making it suitable for optional components. Conversely, require is used for essential components, halting execution if the file is missing or fails to load.

PHP developer interview questions

Intermediate-level PHP projects require a little more than PHP basics. You need to know some advanced topics to successfully complete them as well as some knowledge of additional technologies like MySQL, jQuery, etc. Once you’re ready to work with PHP, it’s time to indulge in PHP projects.

What types of functions are commonly used in PHP?

PHP allows for both user-defined functions, as well as internal (built-in) functions. Popular examples of a built-in function are ‘echo’ and ‘print,’ which are commonly used. Other internal functions include image, string, and variable functions. Because the variables in the $_REQUEST array are provided to the PHP script via COOKIE, GET, and POST input mechanisms, it could be modified by the remote user. The variables and their order listed in the $_REQUEST array is defined in the PHP variables_order configuration directive.

Let’s begin with the first section of PHP interview questions. There are many file-related functions in PHP that developers use for file operations. Candidates should know that “fopen()” is the function that opens https://wizardsdev.com/en/vacancy/middle-php-developer/ files in PHP. They may explain that the “$filename” and “$mode” arguments form parts of this essential function. Senior-level PHP developers should know that they can use a “cURL” to connect a URL to PHP.

This comprehensive guide will help you prepare for all aspects of the interview process.

It is automatically called when a method is invoked that is not accessible or does not exist. In PHP, a magic method is a special method with a predefined name that provides class-specific functionality. It is automatically invoked by PHP in response to certain events or actions. Escaping strings is necessary to prevent syntax errors in your PHP code, which can lead to security vulnerabilities if not handled correctly. It is helpful when working with user input or data from external sources, like databases that may contain malicious code or characters that could break your PHP code.

PHP developer interview questions

Essentially, $$message allows you to dynamically create and access variables based on the value of another variable. This operator is helpful when you need to conditionally perform actions based on the type of an object in your code. In PHP, the break statement is used to terminate the execution of a loop or switch statement. When encountered, it immediately exits the loop or switch and program control moves to the next statement after the loop or switch block.

What are include () and require () functions?

PHP Engine creates a logical object to preserve data across subsequent HTTP requests, which is known as session. PHP setcookie() function is used to set cookie with HTTP response. Once the cookie is set, you can access it by $_COOKIE superglobal variable. It means you can pass 0, 1 or n number of arguments in function.

  • In PHP, the __sleep() method is a magic method used for customizing the serialization process of an object.
  • The session unregister() function frees all session variables while the session unset() function unregisters a global variable from the current session.
  • It is automatically called when an object is cloned using the clone keyword.
  • Be sure to also explain the process you used to troubleshoot and the steps you took to ensure the application was working correctly.
  • Error handling is an important part of writing code in any language, but especially in a web development language like PHP.
  • PEAR (PHP Extension and Application Repository) is a framework and distribution system for reusable PHP components.

This is particularly useful when we are creating an immutable class like the String class.Properties cannot be declared final, only classes and methods may be declared as final. The variable names are case-sensitive but function names are not. If you define the function name in lowercase and call them in uppercase, it will still work.

$message is a regular variable, which has a fixed name and fixed value, whereas a $$message is a reference variable, which stores data about the variable. The value of $$message can change dynamically as the value of the variable changes.

Set_time_limit (0), added at the beginning of the script, sets an infinite execution time so that there is no PHP error „maximum execution time exceeded“. The Include () function is used to put data from one PHP file into another PHP file. If errors occur, the include () function issues a warning but does not stop the script execution, and it will continue execution. The function parse_ini_file() enables us to load in the ini file specified in filename and returns the settings in it in an associative array. The scope of a variable is the context within which it is defined.