Scala: what is the best way to append an element to an Array?

Question

Say I have an Array[Int] like

val array = Array( 1, 2, 3 )

Now I would like to append an element to the array, say the value

Answer 1

The easiest might be:

Array(1, 2, 3) :+ 4

Actually, Array can be implcitly transformed in a WrappedArray

Answer 2

val array2 = array :+ 4
//Array(1, 2, 3, 4)

Works also "reversed":

val array2 = 4 +: array
Array(4, 1, 2, 3)

There is also an "in-place" version:

var array = Array( 1, 2, 3 )
array +:= 4
//Array(4, 1, 2, 3)
array :+= 0
//Array(4, 1, 2, 3, 0)

Answer 3

You can use :+ to append element to array and +: to prepend it:

0 +: array :+ 4

should produce:

res3: Array[Int] = Array(0, 1, 2, 3, 4)

It's the same as with any other implementation of Seq.