ArrayList Size in Kotlin

We can get the size of an ArrayList using the .size property:

val ourArray = mutableListOf(50, 40, 30)

// Printing the size:
println(ourArray.size) // Output: 3

// Changing the ArrayList:
ourArray.removeAt(2)

// Printing the new size:
println(ourArray.size) // Output: 2

Using the size

We can use the size to access items from the end of an ArrayList.

Because ArrayLists are 0-indexed, the index of the last item is size - 1:

val ourArray = mutableListOf(50, 40, 30)

val size = ourArray.size

// Printing the last item:
println(ourArray[size - 1]) // Output: 30

// Printing the second to last item:
println(ourArray[size - 2]) // Output: 40

Assignment
Follow the Coding Tutorial and let's play with some arrays.

Hint
Look at the examples above if you get stuck.