Intro to Scala – Get Started with Typesafe Activator – Immutability
Intro to Scala – Get Started with Typesafe Activator – Immutability
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intro-to-scala
On Github jamesward / intro-to-scala
Intro to Scala
Get Started with Typesafe Activator
Download Activator: http://typesafe.com/platform/getstarted Extract & launch Activator:activator new(or launch the UI from your file browser) Create a new app with the Hello, Scala template
Run the app once:
activator run
Run the app continuously:
activator ~run
Launch the Scala REPL:
activator console
Run the tests continuously:
activator ~test
Immutability
Non-side-effecting and concurrency friendly
val foo: String = "asdf"
Type Inference
Type Safety with less Typing
val foo = "asdf"
val listOfInt: List[Int] = List(1,2,3)
Case Classes
Value Objects Done Right
case class Foo(name: String)
- Concise Syntax
- Built-in toString, equals, hash-code, extractor, creator, copy
val foo = Foo("asdf")
val foo1 = Foo.apply("asdf")
val foo2 = new Foo("asdf")
val bar = foo.copy("zxvc")
Optional Values
Say Goodbye to Null Pointer Exceptions
val asdf: Option[String] = Some("asdf")
val notta: Option[String] = None
Higher Order Functions
Functions are a thing
def stringLength(s: String): Int = s.length
Functions can take other functions as params
def stringTransformer(s: String, f: String => Int): Int = f(s)
The map() function transforms each item in a container
List("a","bb","ccc").map(stringLength)
Anonymous functions
List("a","bb","ccc").map(s => s.length)