In addition to Scala's Array.size gotcha, prefer .length to .size with ListBuffers

ListBufferSizeVsLength.scala

def timeit(fn: () => Any, times: Int = 100000) {
  val start = System.currentTimeMillis
  for (_ <- 0 until times) {
    fn()
  }
  val end = System.currentTimeMillis
  println((end - start) + "ms")
}

val n = 10000
val listBuffer = collection.mutable.ListBuffer(0.until(10000).toSeq:_*)
timeit(() => listBuffer.size)
timeit(() => listBuffer.length)

// From my computer:
//
// $ scala ListBufferSizeVsLength.scala 
// 2984ms
// 9ms