PHP Interview Questions and Answers

What is PHP?
The PHP Hypertext Preprocessor is a programming language that allows web developers to create dynamic content that interacts with databases. PHP is basically used for developing web based software applications.
What are the differences between Get and post methods?
There are some defference between GET and POST method 1. GET Method have some limit like only 2Kb data able to send for request But in POST method unlimited data can we send 2. when we use GET method requested data show in url but Not in POST method so POST method is good for send sensetive request
What are the differences between require and include?
Both include and require used to include a file but when included file not found Include send Warning where as Require send Fatal Error .
What is use of header() function in php ?

The header() function sends a raw HTTP header to a client.We can use header() 
function for redirection of pages. It is important to notice that header() must
be called before any actual output is seen.

What is meant by nl2br()?

Inserts HTML line breaks (<BR />) before all newlines in a strin

How we get IP address of client, previous reference page etc ?

How can we register the variables into a session?
$_SESSION['name'] = 'me';
What are the different types of error in php?

three basic types of runtime errors in PHP:

1. Notices: These are trivial, non-critical errors that PHP encounters while executing a
script for example, accessing a variable that has not yet been defined.
By default, such errors are not displayed to the user at all although 
you can change this default behavior.

2. Warnings: These are more serious errors for example, attempting to include() a file 
which does not exist. By default, these errors are displayed to the user, but they do 
not result in script termination.

3. Fatal errors: These are critical errors  for example, instantiating an object of a non-existent class,
or calling a non-existent function. These errors cause the immediate termination of the script, and PHP 
default behavior is to display them to the user when they take place.