Scala program to add elements to the HashMap collection

Program/Source Code:

The source code to add elements to the HashMap collection is given below. The given program is compiled and executed on the ubuntu 18.04 operating system successfully.

// Scala program to add elements to the
// HashMap collection

import scala.collection.immutable._

object Sample {
  // Main method
  def main(args: Array[String]) {
    var students = HashMap((101, "Amit"), (102, "Arun"), (103, "Anit"))
    
    println("Student Information:");
    for ((stuId, stuName) <- students)
      printf("\tId: %d, Name: %s\n", stuId, stuName);
    
    students = students + (104 -> "Sumit")
    students = students + (105 -> "Kishan")
    
    println("Student Information After adding elements:");
    for ((stuId, stuName) <- students)
      printf("\tId: %d, Name: %s\n", stuId, stuName);
  }
}

Output:

Student Information:
	Id: 101, Name: Amit
	Id: 102, Name: Arun
	Id: 103, Name: Anit
Student Information After adding elements:
	Id: 101, Name: Amit
	Id: 102, Name: Arun
	Id: 105, Name: Kishan
	Id: 103, Name: Anit
	Id: 104, Name: Sumit

Explanation:

Here, we used an object-oriented approach to create the program. And, we imported Collection classes using the below statement,

import scala.collection.mutable._

And, we also created a singleton object Sample and defined the main() function. The main() function is the entry point for the program.

In the main() function, we created a HashMap collection students. The students collection contains student id and student name. Then we added elements to the students HashMap using the "+" operator and printed the updated collection on the console screen.