3 Variables
Variables are declared using the var keyword
In many cases, the type information can be omitted, thanks to Scala’s type inference
To declare a variable with explicit type, put the type after the variable name following a colon :
e.g.
var x: Int = 1 + 2
Tip: Adding explicit type is a matter of preference, in one hand it helps "documenting" your code, on the other hand it might make it more "cluttered". Use judgment, e.g. add explicit types to public interfaces and APIs, and skip it for internal implementation.