PHP Intermediate Interview Questions
  1. What are namespaces in PHP and how do you use them?
  2. How do you handle exceptions in PHP?
  3. What are traits in PHP and how do you use them?
  4. What is autoloading in PHP and how does it work?
  5. What are the different types of design patterns used in PHP?
  6. What is a closure in PHP and how do you use it?
  7. What is an anonymous function in PHP and how do you use it?
  8. What is the difference between "include" and "require" in PHP?
  9. What is the purpose of the "yield" keyword in PHP?
  10. What are the different types of HTTP request methods in PHP?
  11. What is the purpose of the "header" function in PHP?
  12. What is the difference between "echo" and "print" in PHP?
  13. What is the purpose of the "mysqli" extension in PHP?
  14. What is the purpose of the "PDO" extension in PHP?
  15. What is the difference between "mysqli" and "PDO" in PHP?
  16. What is the difference between "htmlentities" and "htmlspecialchars" in PHP?
  17. What is a callback function in PHP and how do you use it?
  18. Write a PHP program to check if a string is a palindrome.
  19. Write a PHP program to sort an array in ascending order.
  20. Write a PHP program to remove duplicates from an array.
  21. Write a PHP program to calculate the Fibonacci sequence.
  22. Write a PHP program to find the factorial of a number using recursion.
  23. Write a PHP program to find the second largest number in an array.
  24. Write a PHP program to create a simple calculator that can perform addition, subtraction, multiplication, and division.
  25. Write a PHP program to count the number of occurrences of a specific word in a string.
  26. Write a PHP program to find the length of the longest word in a sentence.
  27. Write a PHP program to check if a string is a valid email address.
  28. What is the difference between "abstract classes" and "interfaces" in PHP?
  29. How do you handle file uploads in PHP?
  30. How do you handle cross-site scripting (XSS) attacks in PHP?
  31. What is the difference between "cookie" and "session" in PHP?
  32. How do you implement pagination in PHP?
  33. What is object-oriented programming (OOP) and how is it used in PHP?
  34. What is the purpose of the "spl_autoload_register" function in PHP?
  35. How do you implement a singleton design pattern in PHP?
  36. What is the difference between "public", "private", and "protected" in PHP?
  37. How do you implement a "try-catch" block in PHP?
  38. What is the purpose of the "Dependency Injection" design pattern in PHP, and how do you implement it?
  39. How do you secure a PHP application against SQL injection attacks?
  40. What is the purpose of the "Composer" package manager in PHP, and how do you use it?
  41. What is the difference between a "session" and a "cookie" in PHP, and when would you use each?
  42. What is the purpose of the "PHP Data Objects" (PDO) extension, and how do you use it?
  43. How do you create a RESTful API in PHP, and what are some common best practices for doing so?
  44. What is the difference between a "regular expression" and a "wildcard expression" in PHP, and how do you use them?
  45. How do you implement a "Model-View-Controller" (MVC) architecture in a PHP application, and what are some of the benefits of doing so?
  46. What is the purpose of the "getopt" function in PHP, and how do you use it to handle command line arguments?
  47. How do you implement an "Observer" design pattern in PHP, and what are some common use cases for it?
PHP Interview Questions For Experienced
  1. What are anonymous classes in PHP and how do you use them?
  2. What is the difference between "public", "private", and "protected" in PHP?
  3. What is the purpose of the "use" keyword in PHP namespaces?
  4. What is the difference between a "factory" and an "abstract factory" design pattern in PHP?
  5. What is the purpose of the "array_map" function in PHP and how is it used?
  6. What is the purpose of the "try-catch-finally" block in PHP?
  7. Write a PHP program to find the largest sum of contiguous subarray in an array.
  8. Write a PHP program to find the common elements between two arrays.
  9. Write a PHP program to implement a binary search algorithm.
  10. Write a PHP program to implement a bubble sort algorithm.
  11. Write a PHP program to implement a merge sort algorithm.
  12. Write a PHP program to find the prime numbers between 1 and 100.
  13. Write a PHP program to implement a queue data structure.
  14. Write a PHP program to implement a stack data structure.
  15. Write a PHP program to implement a linked list data structure.
  16. Write a PHP program to implement a hash table data structure.
  17. Write a PHP program to implement a binary tree data structure.
  18. Write a PHP program to implement a depth-first search algorithm.
  19. Write a PHP program to implement a breadth-first search algorithm.
  20. Write a PHP program to find the longest common subsequence of two strings.
  21. Write a PHP program to find the shortest distance between two points on a grid.
  22. What is the difference between "REST" and "SOAP" in web services?
  23. How do you implement a microservices architecture in PHP?
  24. How do you implement a caching mechanism in PHP?
  25. What is the purpose of the "memcached" extension in PHP?
  26. What is the purpose of the "Redis" database in PHP?
  27. What is the difference between "mysqli" and "PDO" in PHP?
  28. What is the purpose of the "filter_var" function in PHP?
  29. How do you implement a message queue in PHP?
  30. How do you implement a load balancer in PHP?
  31. How do you optimize the performance of a PHP application?
  32. How do you scale a PHP application to handle high traffic loads, and what are some of the challenges involved?
  33. What is the purpose of the "PHP Extension Community Library" (PECL), and how do you use it to extend the functionality of PHP?
  34. What is the difference between "SOAP" and "REST" web services, and what are some advantages and disadvantages of each?
  35. How do you implement an "Adapter" design pattern in PHP, and what are some common use cases for it?
  36. What is the purpose of the "Gearman" job server in PHP, and how do you use it to implement background tasks?
  37. How do you implement a "Service Locator" design pattern in PHP, and what are some common use cases for it?
  38. How do you use "Composer" to manage dependencies in a PHP application, and what are some best practices for doing so?
  39. What is the purpose of the "Xdebug" debugger in PHP, and how do you use it to debug a PHP application?
  40. What is the purpose of the "HipHop Virtual Machine" (HHVM), and how does it improve the performance of PHP applications?
  41. How do you use "PHPUnit" to write unit tests for a PHP application, and what are some best practices for doing so?