The 'takeWhile' function is a useful Kotlin standard library function that allows you to take elements from a collection while a specified condition holds true. This is particularly handy when you want to filter a collection based on a certain criterion until the first element that does not satisfy the condition is encountered.
val numbers = listOf(1, 2, 3, 4, 3, 2, 1)
val result = numbers.takeWhile { it < 4 }
// result will be [1, 2, 3]