Open In App

HashSet In Scala

Improve
Improve
Like Article
Like
Save
Share
Report

HashSet is sealed class. It extends immutable Set and AbstractSet trait. Hash code is used to store elements. It neither sorts the elements nor maintains insertion order . The Set interface implemented by the HashSet class, backed by a hash table . In Scala, A concrete implementation of Set semantics is known HashSet.
Syntax:

var HashsetName = HashSet(element1, element2, element3, ....)  

Operations perform with HashSet

  • Initialize a HashSet : Below is the example to create or initialize HashSet.
    Example :




    // Scala program of Initializing HashSet
    import scala.collection.immutable.HashSet
      
    // Creating object
    object GFG
        // Main method
        def main(args:Array[String])
        
            println("Initialize a HashSet")
              
            // Creating HashSet
            val hashSet: HashSet[String] = HashSet("Geeks",
                                        "GeeksForGeeks", "Author")
            println(s"Elements are = $hashSet")
        }

    
    

    Output:

    Initialize a HashSet
    Elements are = Set(Geeks, Author, GeeksForGeeks)
  • Check specific elements in HashSet :
    Example :




    // Scala program of Check specific elements in HashSet
    import scala.collection.immutable.HashSet
      
    // Creating object
    object GFG
        // Main method
        def main(args:Array[String])
        
            println("Initialize a HashSet")
              
            // Creating HashSet
            val hashSet: HashSet[String] = HashSet("Geeks",
                                    "GeeksForGeeks", "Author")
            println(s"Elements are = $hashSet")
              
            // Checking
            println(s"Element Geeks = ${hashSet("Geeks")}")
            println(s"Element Student = ${hashSet("Student")}")
        }

    
    

    Output:

    Initialize a HashSet
    Elements are = Set(Geeks, Author, GeeksForGeeks)
    Element Geeks = true
    Element Student = false
    
  • Adding an elements in HashSet : We can add an element in HashSet by using + sign. below is the example of adding an element in HashSet.
    Example :




    // Scala program of adding an element in HashSet
    import scala.collection.immutable.HashSet
      
    // Creating object
    object GFG
        // Main method
        def main(args:Array[String])
        
            println("Initialize a HashSet")
              
            // Creating HashSet
            val hs: HashSet[String] = HashSet("Geeks",
                                "GeeksForGeeks", "Author")
            println(s"Elements are = $hs")
              
            // Adding an element in HashSet
            val hs1: HashSet[String] = hs + "GeeksClasses"
            println(s"Adding elements to HashSet = $hs1")
        }
    }

    
    

    Output:

    Initialize a HashSet
    Elements are = Set(Geeks, Author, GeeksForGeeks)
    Adding elements to HashSet = Set(GeeksClasses, Geeks, Author, GeeksForGeeks)
    
  • Adding more than one element in HashSet : We can add more than one element in HashSet by using ++ sign. below is the example of adding more than one elements in HashSet.
    Example :




    // Scala program of adding more elements in HashSet
    import scala.collection.immutable.HashSet
      
    // Creating object
    object GFG
        // Main method
        def main(args:Array[String])
        
            println("Initialize a HashSet")
              
            // Creating HashSet
            val hs: HashSet[String] = HashSet("Geeks",
                                    "GeeksForGeeks", "Author")
            println(s"Elements are = $hs")
              
            // Adding elements in HashSet
            val hs1: HashSet[String] = hs ++ HashSet[String]("Java", "Scala")
            println(s"Add more than one HashSets = $hs1")
        }
    }

    
    

    Output:

    Initialize a HashSet
    Elements are = Set(Geeks, Author, GeeksForGeeks)
    Add more than one HashSets = Set(Scala, Geeks, Author, Java, GeeksForGeeks)
    
  • Remove element in HashSet : We can remove an element in HashSet by using – sign. below is the example of removing an element in HashSet.
    Example :




    // Scala program of removing element in HashSet
    import scala.collection.immutable.HashSet
      
    // Creating object
    object GFG
        // Main method
        def main(args:Array[String])
        
            println("Initialize a HashSet")
              
            // Creating HashSet
            val hs: HashSet[String] = HashSet("Geeks",
                                    "GeeksForGeeks", "Author")
            println(s"Elements are = $hs")
              
            // removing elements in HashSet
            val hs1: HashSet[String] = hs - "Geeks"
            println(s"remove element from hashset = $hs1")
        }
    }

    
    

    Output:

    Initialize a HashSet
    Elements are = Set(Geeks, Author, GeeksForGeeks)
    remove element from hashset = Set(Author, GeeksForGeeks)
  • Find the intersection between two HashSets : We can find intersection between two HashSets by using & sign. below is the example of finding intersection between two HashSets.
    Example :




    // Scala program of finding the intersection between two HashSets
    import scala.collection.immutable.HashSet
      
    // Creating object
    object GFG
        // Main method
        def main(args:Array[String])
        
            println("Initialize two HashSets")
              
            // Creating two HashSet
            val hs: HashSet[String] = HashSet("Geeks",
                                "GeeksForGeeks", "Author")
            println(s"Elements of hashset1 are = $hs")
              
            val hs1: HashSet[String] = HashSet("Java"
                                        "Geeks", "Scala")
            println(s"Elements of hashset2 are = $hs1")
              
            // finding the intersection between two HashSets
            println(s"Intersection of hashSet1 and hashSet2 = ${hs & hs1}")
        }
    }

    
    

    Output:

    Initialize two HashSets
    Elements of hashset1  are = Set(Geeks, Author, GeeksForGeeks)
    Elements of hashset2 are = Set(Scala, Geeks, Java)
    Intersection of hashSet1 and hashSet2 = Set(Geeks)
    
  • Initializing an empty HashSet :
    Example :




    // Scala program of  Initializing an empty HashSet
    import scala.collection.immutable.HashSet
      
    // Creating object
    object GFG
        // Main method
        def main(args:Array[String])
        
            // Initializing an empty HashSet
            val emptyHashSet: HashSet[String] = HashSet.empty[String]
            println(s"Empty HashSet = $emptyHashSet")
        }
    }

    
    

    Output:

    Empty HashSet = Set()


Last Updated : 04 Jul, 2019
Like Article
Save Article
Previous
Next
Share your thoughts in the comments
Similar Reads