How to use SortBy for Sorting a Map Value In Scala

Using SortBy for Sorting By the Second Attribute

In this approach, we are using the sortBy function in Scala to sort a map by its values (ages).
First, we convert the map people into a sequence using people.toSeq, then we use sortBy(_._2) as the sorting criteria, where _._2 represents the values (ages) of each key-value pair in the map.
Next, we convert the sorted sequence back into a ListMap to preserve the sorted order by values.
Finally, we print the sorted map of people by their ages using foreach(println), which prints each key-value pair in the sorted map on a new line.

In the below example, the sortBy is used for sorting a map value.

Scala

// Importing required libraries
import scala.collection.immutable.ListMap

// Creating Object
object GFG {

  // Main Method
  def main(args: Array[String]): Unit = {
    // Creating a map of key-value pairs (name -> age)
    val people = Map("GFG1" -> 25, "GFG2" -> 30, "GFG3" -> 20, "GFG4" -> 35)

    // Sorting the map by values in ascending order using sortBy
    val sortedPeople = ListMap(people.toSeq.sortBy(_._2):_*)

    // Printing the sorted map
    println("Sorted People (By Age):")
    sortedPeople.foreach { case (name, age) =>
      println(s"$name -> $age")
    }
  }
}

Output:

How to Use Sortby in Scala?

In this article, we will learn to use the sortBy function in Scala. The sortBy function is used to sort elements in a collection based on specified sorting criteria.

Table of Content

Using SortBy for Sorting an Array
Using SortBy for Sorting an Array in Reverse Order
Using SortBy for Sorting By the Second Attribute
Using SortBy for Sorting a Map Value

Syntax:

collection.sortBy(function)

Here,

collection: The collection (such as an array, list, map, etc.) that you want to sort.

function: A function that defines the sorting criteria. This function takes an element from the collection and returns the value by which the elements should be sorted.

How to use SortBy for Sorting a Map Value In Scala

How to Use Sortby in Scala?

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