GET Method:get method is used for submitting small amount of data. Data shows in the URL, so it is not secure.
POST Method:post method is used for submitting small amount of data. Data does not show URL, so it is  secure.

Ans: The symbolic representation of data is called regular expression. 
The syntax of regular expression is:
Variable_name.method_name(/searching_word/modifiers,”parsed_value”);

Cross-site scripting (XSS) is a type of computer security vulnerability typically found in web applications which allow code injection by malicious web users into the web pages viewed by other users. 

Examples of such code include HTML code and client-side scripts. SQL injection is a code injection technique that exploits a security vulnerability occurring in the database layer of an application.

The vulnerability is present when user input is either incorrectly filtered for string literal escape characters embedded in SQL statements or user input is not strongly typed and thereby unexpectedly executed

Ans: r+,W, w+, A, a+, X,x+

Class: Classes are intended to represent those real-life items that coder like to manipulate within an application.
object: An instance of class is called object.