learnxinyminutes-docs/scala.html.markdown
2013-07-28 20:52:32 +01:00

1.3 KiB

/* Set yourself up:

  1. Download Scala - http://www.scala-lang.org/downloads
  2. unzip/untar in your favourite location and put the bin subdir on the path
  3. Start a scala REPL by typing scala. You should see the prompt:

scala>

This is the so called REPL. You can run commands in the REPL. Let do just that: */

println(10) // prints the integer 10

println("Boo!") // printlns the string Boo!

// Evaluating a command gives you the type and value of the result

1 + 7

/* The above line results in:

scala> 1 + 7 res29: Int = 8

This means the result of evaluating 1 + 7 is an object of type Int with a value of 8

1+7 will give you the same result */

// Everything is an object, including a function type these in the repl:

7 // results in res30: Int = 7 (res30 is just a generated var name for the result)

// The next line gives you a function that takes an Int and returns it squared (x:Int) => x * x

// You can assign this function to an identifier, like this: val sq = (x:Int) => x * x

/* The above says this

sq: Int => Int =

Which means that this time we gave an explicit name to the value - sq is a function that take an Int and returns Int.

sq can be executed as follows: */

sq(10) // Gives you this: res33: Int = 100. The result is the Int with a value 100