Common PHP question asked in interview

11. Is multiple inheritance supported in PHP?
PHP includes only single inheritance, it means that a class can be extended from only one single class using the keyword ‘extended’.

12. What is the meaning of a final class and a final method?
‘final’ is introduced in PHP5. Final class means that this class cannot be extended and a final method cannot be overrided.

13. How comparison of objects is done in PHP5?
We use the operator ‘==’ to test is two object are instanced from the same class and have same attributes and equal values. We can test if two object are refering to the same instance of the same class by the use of the identity operator ‘===’.

14. How can PHP and HTML interact?
It is possible to generate HTML through PHP scripts, and it is possible to pass informations from HTML to PHP.

15. What type of operation is needed when passing values through a form or an URL?
If we would like to pass values througn a form or an URL then we need to encode and to decode them using htmlspecialchars() and urlencode().

16. How can PHP and Javascript interact?
PHP and Javascript cannot directly interacts since PHP is a server side language and Javascript is a client side language. However we can exchange variables since PHP is able to generate Javascript code to be executed by the browser and it is possible to pass specific variables back to PHP via the URL.

17. What is needed to be able to use image function?
GD library is needed to be able execute image functions.

18. What is the use of the function ‘imagetypes()’?
imagetypes() gives the image format and types supported by the current version of GD-PHP.

19. What are the functions to be used to get the image’s properties (size, width and height)?
The functions are getimagesize() for size, imagesx() for width and imagesy() for height.

20. How failures in execution are handled with include() and require() functions?
If the function require() cannot access to the file then it ends with a fatal error. However, the include() function gives a warning and the PHP script continues to execute.