5.1: Extensions

Question 1

Which one of the following returns a copy of a list?

• add()

• remove()

• reversed()

• contains()

Question 2

Which one of these extension functions on class AquariumPlant(val color: String, val size: Int, private val cost: Double, val leafy: Boolean) will give a compiler error?

• fun AquariumPlant.isRed() = color == "red"

• fun AquariumPlant.isBig() = size > 45

• fun AquariumPlant.isExpensive() = cost > 10.00

• fun AquariumPlant.isNotLeafy() = leafy == false

Question 3

Which one of the following is not a place where you can define constants with const val?

• at the top level of a file

• in regular classes

• in singleton objects

• in companion objects