filter().headOption as find()23
24 def pickFirst1(arr: Array[Int], criteria: Int => Boolean): Int = arr.filter(criteria).head
25 def pickFirst2(arr: Array[Int], criteria: Int => Boolean): Option[Int] =
26 arr.filter(criteria).headOption27 def pickInAnOrder(arr: Array[Int], criteria: Int => Boolean): Array[Int] =
28 arr.sortWith(_ < _).filter(criteria)
29The scala analyzer has determined that this collection method chain can be simplified into a single call to find().
Scala collections such as List and ArrayBuffer implement a number of processing methods -
1. .filter - allows you to select elements from your collection based on the condition specified.
2. .find - returns the first element that satisfies your condition as an Option.
3. .headOption - returns the first element from your collection as an Option.
While .find behaves in the exact same manner as .filter().headOption, it performs slightly better as it terminates after finding the first element that satisfies your condition while .filter continues to iterate through the entire collection. It is therefore suggested that you rewrite .filter().headOption as .find.
Bad practice
val firstEven = nums.filter(x => x % 2 == 0).headOption
Recommended
val firstEven = nums.find(x => x % 2 == 0)