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Scala program to iterate HashMap collection using the for loop

Here, we are going to learn how to iterate HashMap collection using the for loop in Scala programming language?
Submitted by Nidhi, on June 10, 2021 [Last updated : March 11, 2023]

Scala - Iterating HashMap (Using For Loop)

Here, we will create two maps using the HashMap collection. The HashMap collection stores elements in key/value pairs. It uses hash code to store elements and return a map. Then iterate Map collection using the for loop and print on the console screen.

Scala code to iterate HashMap collection using the for loop

The source code to iterate HashMap using the for loop is given below. The given program is compiled and executed on the ubuntu 18.04 operating system successfully.

// Scala program to iterate 
// HashMap collection using "for" loop

import scala.collection.mutable._

object Sample {
  // Main method
  def main(args: Array[String]) {
    var students = HashMap(("101", "Amit"), ("102", "Arun"), ("103", "Anit"))
    var employees = HashMap((1001, "Akash"), (1002, "Vikas"), (1003, "Prakash"))

    println("Student Information:");
    for ((stuId, stuName) <- students)
      printf("\tId: %s, Name: %s\n", stuId, stuName);

    println("Employee Information:");
    for ((empId, empName) <- employees)
      printf("\tId: %d, Name: %s\n", empId, empName);
  }
}

Output

Student Information:
	Id: 101, Name: Amit
	Id: 102, Name: Arun
	Id: 103, Name: Anit
Employee Information:
	Id: 1001, Name: Akash
	Id: 1002, Name: Vikas
	Id: 1003, Name: Prakash

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 two HashMap collections students and employees. The students collection contains student id and student name. The employees collection contains employee id and employee name. After that, we printed both collections on the console screen.

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