Sequence operation chains, on the other hand, do not have a need to create these intermediate collections. You might recall that collection operations chains create an intermediate collection in between the operations: So keep that in mind as we explore these factors! Factor #1: Operation CountĪs you know, collection and sequence operations such as filter(), map(), and take() can be linked together into an operation chain, like this: Keep in mind that multiple factors often will be in play at one time - one factor will tip the scales in one direction, but the next factor might tip it farther in the other direction.Īlso, it’s critical to understand that unless you actually run benchmarks on your specific code with true-to-life data, you can’t know for sure. Knowing these factors - and how they combine - can be a helpful starting point for understanding when sequences might be a better choice than collections. It’s helpful to think of these factors as weights on a scale - some factors will tend to tip the scales in favor of sequences, and some will tend to tip the scales in favor of collections. There are a few main factors that can affect performance. In fact, in many cases, collections can be more efficient than sequences! But there are certain characteristics that can totally blindside you if you’re not aware of them. Yes, sequences are known for their performance benefits over standard collection operations. And if you’re looking to understand exactly how they’re implemented, you should take a look at the second article, Inside Kotlin Sequences.Īll caught up? Great - let’s go! Sequences vs.

If you’re asking yourself what a sequence is, you should definitely read the first article in this series, Kotlin Sequences: An Illustrated Guide. Then, we’ll look at how Kotlin’s sequences stack up against Java streams, a similar concept. That’s the question we’re going to answer in this third and final article in this series! We’re going to look at the trade-offs of each, including the main things that affect their performance.

“When should I use sequences, and when should I use normal collections?”

One of the most common questions I get about Kotlin’s sequences is this:

Arraylist kotlin