Scala Collections - Partition Method

partition() method is a member of TraversableLike trait, it is used to run a predicate method on each elements of a collection. It returns two collections, one collection is of elements which satisfiles a given predicate function and another collection is of elements which do not satisfy the given predicate function.

Syntax

The following is the syntax of map method.

def partition(p: (A) ? Boolean): (Repr, Repr)

Here, partition method takes a prediate function as a parameter. This method returns the collections.

Usage

Below is an example program of showing how to use partition method −

Example

object Demo {
   def main(args: Array[String]) = {
      val list = List(1, 2, 3, 4, 5, 6, 7)
      //apply operation to get twice of each element.
      val (result1, result2) = list.partition(x=>{x % 3 == 0})
      //print result
      println(result1)
      println(result2)      
   }
}

Save the above program in Demo.scala. The following commands are used to compile and execute this program.

Command

\>scalac Demo.scala
\>scala Demo

Output

List(3, 6)
List(1, 2, 4, 5, 7)