1.How we declare variables in Swift ?
 Answer:

Before using constants and variables,we must declare them .

Declare constants with the 'let' keyword and variables with the 'var' keyword.

​An NSMutableArray is an NSArray is a subclass of NSArray.But,we can really
​another immutable instance by the following way.In this post, I have shared some examples - how to turn a swift Array to Mutable Array or vice versa.This is my first article in swift for the beginners.Feel free to share your comments.