PHP: Interview Questions PART-2
Is multiple inheritance supported in PHP?
PHP supports only single inheritance; it means that a class can be extended from only one single class using the keyword 'extended'.
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 overridden.
How is the comparison of objects done in PHP?
We use the operator '==' to test is two objects are instanced from the same class and have same attributes and equal values. We can test if two objects are referring to the same instance of the same class by the use of the identity operator '==='.
How can PHP and HTML interact?
It is possible to generate HTML through PHP scripts, and it is possible to pass pieces of information from HTML to PHP.
What type of operation is needed when passing values through a form or an URL?
If we would like to pass values through a form or an URL, then we need to encode and to decode them using htmlspecialchars() and urlencode().
What is needed to be able to use image function?
GD library is needed to execute image functions.
What is the use of the function 'imagetypes()'?
imagetypes() gives the image format and types supported by the current version of GD-PHP.
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.
How failures in execution are handled with include() and require() functions?
If the function require() cannot access the file then it ends with a fatal error. However, the include() function gives a warning, and the PHP script continues to execute.