List Operations

Transforming Lists

Kotlin lists have powerful higher-order methods:

map — transform each element

val nums = listOf(1, 2, 3, 4, 5)
val doubled = nums.map { it * 2 }  // [2, 4, 6, 8, 10]

filter — keep elements that match

val evens = nums.filter { it % 2 == 0 }  // [2, 4]

fold — accumulate into a single value

val sum = nums.fold(0) { acc, x -> acc + x }  // 15

any / all

nums.any { it > 4 }   // true
nums.all { it > 0 }   // true

Your Turn

Given the list [1, 2, 3, 4, 5, 6], print the list of squares, then the list of odd numbers, then the sum of all elements.