Consider combining successive
.filter() calls SC-P1009
Performance
Major
a month ago
—
2 years old
Consider combining both the
filters11 def exists(arr: Array[Int], criteria: Int => Boolean): Boolean = arr.find(criteria).isDefined
12 def filterBy(arr: Array[Int], criteria: Int => Boolean): Array[Int] = arr.filter(criteria)
13 def filterBy(arr: Array[Int], first: Int => Boolean, `then`: Int => Boolean): Array[Int] =
14 arr.filter(first).filter(`then`)15
16 def pickBy(arr: Array[Int], criteria: Int => Boolean): Unit = {
17 for (i <- 0 to arr.length - 1) {
Description
Certain Scala collections support methods such as .filter, allowing you to select elements from your collection based on specified conditions. Since each filter call iterates through the entire collection, it is recommended that you combine/chain such consecutive calls to avoid re-iterations.
Bad practice
val filteredElements = elements.filter(x => x % 2 == 0).filter(x => x >= 4)
Recommended
val filteredElements = elements.filter(x => x % 2 == 0 && x >= 4)