Variables: change is good

var variableName = ...

Variables (like Constants) define a value.
Variables are declared with the keyword "var".
Unlike Constants, Variables can change values.
For you Objective-C types, Variables are Mutable.

// Variable with Type explicitly declared
var greetings: String[] = ["Hi","Aloha","Ciao"]

// Variable defined with String[] Type inference
var greetings = ["Hi","Aloha","Ciao"]

// Variable defined with Double Type inference
var perfect = 10.0

// Declaring multiple Variables at once
var a = 10.0, b = 25.0, c = 52.5