scala for the impatient excercises chapter 3 excercise 2

swap_array.scala

def swap_array(a: Array[Int]) = {
    for (i <- 0 until a.length) {
        if ((i % 2 == 0) && (i+1) < a.length) {
            val t = a(i)
            a(i) = a(i+1)
            a(i+1) = t
        }
    }
    a
}

val a = Array(1,2,3,4,5,6)
println(a.toList)
println(swap_array(a).toList)