Andre Kashliev

Scala

Installed Scala and followed this book:

brew install scala@3

Install IntelliJ and plugin, follow these instructions:

REPL

val vs var (immutable vs mutable)

val b: Byte = 1

val i: Int = 1

val l: Long = 1

val s: Short = 1

val d: Double = 2.0

val f: Float = 3.0

val x = 1_000L // val x: Long = 1000

val y = 2.2D // val y: Double = 2.2

val z = 3.3F // val z: Float = 3.3

When you need really large numbers, use the BigInt and BigDecimal types:

var a = BigInt(1_234_567_890_987_654_321L)

var b = BigDecimal(123_456.789)

String interpolation

val firstName = "John"

val mi = 'C'

val lastName = "Doe"

You can combine those variables in a string like this:

println(s"Name: $firstName $mi $lastName") // "Name: John C Doe"

To embed arbitrary expressions inside a string, enclose them in curly braces:

println(s"2 + 2 = ${2 + 2}") // prints "2 + 2 = 4"

val x = -1

println(s"x.abs = ${x.abs}") // prints "x.abs = 1"

Multiline strings

Multiline strings are created by including the string inside three double-quotes:

val quote = """The essence of Scala:

Fusion of functional and object-oriented

programming in a typed setting."""

for loops and expressions:

val fruits = List("apple", "banana", "lime", "orange")

val fruitLengths = for

f <- fruits

if f.length > 4

yield

// you can use multiple lines

// of code here

f.length

// fruitLengths: List[Int] = List(5, 6, 6)