1. ++/-- var num = 5 println(num++) //5 println(++num) //7 println(num--) //7 println(--num) //5 2. toInt()/toFloat() toInt() : change the type to integer toFloat(): change the type to float println("10" + 6) println(10 + "6".toInt()) //16 val num = 5.6757565765667 println(num) println(num.toFloat()) println(num.toInt()) 3. arrayOf : immutable(cannot be resized) 1) contentToString() val species ..