Example
Arrays are regular JVM arrays with a twist that they are treated as invariant and have special constructors and implicit conversions. Construct them without the new keyword.
val a = Array("element")
Now a has type Array[String].
val acs: Array[CharSequence] = a
//Error: type mismatch; found : Array[String] required: Array[CharSequence]
Although String is convertible to CharSequence, Array[String] is not convertible to Array[CharSequence].
You can use an Array like other collections, thanks to an implicit conversion to TraversableLike ArrayOps:
val b: Array[Int] = a.map(_.length)
Most of the Scala collections (TraversableOnce) have a toArray method taking an implicit ClassTag to construct the result array:
List(0).toArray
//> res1: Array[Int] = Array(0)
This makes it easy to use any TraversableOnce in your Scala code and then pass it to Java code which expects an array.
