Scala Map filterKeys() method with example
The filterKeys() method is utilized to find all the pairs where the keys satisfies the given predicate.
Method Definition: def filterKeys(p: (A) => Boolean): Map[A, B]
Return Type: It returns all the “key-value” pairs of the map where, the keys satisfies the given predicate.
Example #1:
// Scala program of filterKeys()// method // Creating objectobject GfG{ // Main method def main(args:Array[String]) { // Creating map val m1 = Map(5 -> "geeks", 4 -> "for", 2 -> "cs") // Applying filterKeys method val result = m1.filterKeys(_ > 2) // Displays output println(result) }} |
Output:
Map(5 -> geeks, 4 -> for)
Here, only two key-value pairs are returned as their keys are greater than two as per the stated predicate.
Example #2:
// Scala program of filterKeys()// method // Creating objectobject GfG{ // Main method def main(args:Array[String]) { // Creating map val m1 = Map(3 -> "geeks", 1 -> "for", 2 -> "cs") // Applying filterKeys method val result = m1.filterKeys(_ > 3) // Displays output println(result) }} |
Output:
Map()
Here, no pair is returned as none of the keys satisfies the stated predicate.
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