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:

filter_none

edit
close

play_arrow

link
brightness_4
code

// Scala program of filterKeys()
// method
  
// Creating object
object 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)
      
    }
}

chevron_right


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:

filter_none

edit
close

play_arrow

link
brightness_4
code

// Scala program of filterKeys()
// method
  
// Creating object
object 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)
      
    }
}

chevron_right


Output:

Map()

Here, no pair is returned as none of the keys satisfies the stated predicate.




My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.


Article Tags :

Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.