Scala Set is a collection of pairwise different elements of the same type. In other words, a Set is a collection that contains no duplicate elements. HashSet implements immutable sets and uses hash table. Elements insertion order is not preserved.
Declaring HashSet Variables
The following is the syntax for declaring an HashSet variable.
Syntax
var z : HashSet[String] = HashSet("Zara","Nuha","Ayan")
Here, z is declared as an hash-set of Strings which has three members. Values can be added by using commands like the following −
Command
var myList1: HashSet[String] = myList + "Naira";
Processing HashSet
Below is an example program of showing how to create, initialize and process HashSet −
Example
import scala.collection.immutable.HashSet object Demo { def main(args: Array[String]) = { var mySet: HashSet[String] = HashSet("Zara","Nuha","Ayan"); // Add an element var mySet1: HashSet[String] = mySet + "Naira"; // Remove an element var mySet2: HashSet[String] = mySet - "Nuha"; // Create empty set var mySet3: HashSet[String] = HashSet.empty[String]; println(mySet); println(mySet1); println(mySet2); println(mySet3); } }
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
HashSet(Zara, Nuha, Ayan) HashSet(Zara, Nuha, Ayan, Naira) HashSet(Zara, Ayan) HashSet()