PHP Interview Questions

PHP Interview Questions

1. What is PHP and what is it used for?

PHP is a scripting language primarily used for server-side web development. It allows you to create dynamic web pages, handle user input, connect to databases, and process information.

2. What are the different data types in PHP?

There are eight basic data types in PHP: integers, floats, strings, booleans, arrays, objects, null, and resources. Each has specific uses and limitations.

3. How are variables declared and used in PHP?

Variables start with a dollar sign (“$”). You can assign values to them using the equal sign (“=”) and access them by their names afterwards. For example, $name = "sam"; defines a variable called $name with the value “sam”.

4. What are the differences between echo and print in PHP?

Both echo and print output data to the screen. However, echo has better performance and can accept multiple arguments without parentheses, while print always returns 1 and requires parentheses for multiple arguments.

5. What are some basic control flow statements in PHP?

PHP offers different control flow statements like if, else, switch, while, do-while, and for loops to control the flow of execution based on conditions.

6. What is HTML form processing in PHP?

When you submit data through a web form, it is sent to the server as key-value pairs. PHP provides functions like $_POST and $_GET to access this data and process it according to your needs.

7. What is the importance of user input validation in PHP?

User input can be malicious or contain errors. Validating user input using techniques like filtering, data type conversion, and regular expressions helps prevent security vulnerabilities and ensures data integrity.

8. Explain the concept of cookies and sessions in PHP.

Cookies are small text files stored on the user’s computer to remember information between visits. Sessions store user data temporarily on the server for the duration of their visit. PHP offers functions to manage both cookies and sessions.

9. What are some popular PHP frameworks and what are their benefits?

Laravel, Symfony, CodeIgniter, and CakePHP are some popular PHP frameworks that provide reusable libraries, pre-built functionalities, and MVC architecture for efficient web development.

10. How can you stay updated with the latest PHP trends and best practices?

Following official PHP documentation, blogs, and online communities, and attending relevant conferences and workshops are good ways to stay updated with the latest trends and best practices in PHP.