Top 11 Must‑Know PHP Interview Questions and Answers

Question: What is PHP in the simplest terms?

Answer: PHP stands for Hypertext Preprocessor, a server‑side scripting language used to develop dynamic websites.

Question: What is MVC?

Answer: MVC consists of Model, View, and Controller. In PHP, MVC helps manage code across these three layers efficiently. Model : Data access layer. View : Presents application data on the interface. Controller : Handles user input, reads from the view, and sends data to the model.

Question: How many ways can CSS be included in a page?

Answer: There are three methods: Linking an external CSS file. Defining internal style blocks. Using inline styles directly on elements.

Question: Does PHP support multiple inheritance?

Answer: No. A PHP class can inherit from only one parent class, using the extends keyword.

Question: What is the difference between echo and print?

Answer: Both output values, but echo can output multiple strings separated by commas and only handles basic types, while print can also return a value and handle function return values.

Question: What are the differences between GET and POST methods?

Answer: GET appends form data to the URL and is limited to about 1024 characters, suitable for small, non‑sensitive data. POST sends data in the request body, allowing up to roughly 2 MB and is better for larger or more secure transmissions.

Question: How to get image dimensions in PHP?

Answer: Use getimagesize() to obtain width and height; imagesx() returns the width, and imagesy() returns the height.

Question: What is PEAR in PHP?

Answer: PEAR (PHP Extension and Application Repository) is a code repository that provides reusable PHP extensions and libraries.

Question: How to upload videos with PHP and MySQL?

Answer: Store the video file path in the database rather than the binary data. Save the video file in a server directory, adjust the upload size limit (default 2 MB) via the upload_max_filesize setting in php.ini if needed.

Question: What types of errors exist in PHP?

Answer: PHP errors fall into three categories: Notice : Minor messages, often harmless, such as accessing an undefined variable. Warning : More serious, displayed to the user but does not halt script execution, e.g., including a missing file. Error : Fatal errors that stop execution, such as referencing an undefined class.

Question: How to define a constant in PHP?

Answer: Use the define() function, e.g., define("Newconstant", 30);

Question: How to submit a form without a submit button?

Answer: Use a hyperlink that triggers form submission via JavaScript, for example: <a href="javascript: document.myform.submit();">Submit Me</a>