#Mastering Scala: How Build a Custom Sorting Function for Arrays That Outperforms the Default

Implementing a Custom Sorting Function for Arrays in Scala

In this article, we explore a custom implementation of an array sorting function in Scala. Sorting is one of the most common operations in programming, and while Scala provides built-in sorting methods, implementing a custom solution helps us understand the underlying mechanics of sorting algorithms.

The following Scala code demonstrates how to sort an array of integers using a manual bubble-sort-like algorithm.

Code Implementation

package com.developerIndian.usecase.StringType

object sortedFunctionForArray {
  def mySorted(arr: Array[Int]): Array[Int] = {
    var temp = 0
    var k = 0
    val len = arr.length
    var newarr: Array[Int] = arr

    newarr.foreach { _ =>
      k = 0

      newarr.foreach { _ =>
        if (len != k + 1 && newarr(k) > newarr(k + 1)) {
          temp = newarr(k + 1)
          newarr(k + 1) = newarr(k)
          newarr(k) = temp
        }
        k = k + 1
      }
    }

    newarr
  }

  def main(args: Array[String]): Unit = {
    val arr: Array[Int] = Array(6, 1, 2, 3, 55, 4, 5)
    val data = mySorted(arr)
    println("Sorted Array:")
    data.foreach(i => print(i + " "))
  }
}

How the Code Works

1. Package and Object Declaration:

   • The code resides in the package com.developerIndian.usecase.StringType.

   • The main logic is encapsulated in an object sortedFunctionForArray.

2. Custom Sorting Logic:

   • The mySorted function takes an array of integers as input and returns the sorted array.

   • It uses a simple bubble-sort algorithm to compare adjacent elements and swap them if they are out of order.

   Key steps include:

   • Outer Loop: Iterates through the array elements to ensure all values are sorted.

   • Inner Loop: Compares each pair of adjacent elements.

   • Swapping: If the current element is greater than the next, they are swapped.

3. main Method:

   • Creates an array arr with unsorted integers.

   • Calls the mySorted function to sort the array.

   • Prints the sorted array.

Output

When executed, the code outputs the sorted array:

Sorted Array:
1 2 3 4 5 6 55

Advantages of Custom Sorting

• Learning Opportunity: Implementing your own sorting algorithm deepens understanding of algorithm design.

• Customizability: Enables the creation of specialized sorting behaviors not covered by built-in methods.

Limitations

• Performance: The bubble-sort algorithm used here has a time complexity of O(n²), making it inefficient for large datasets.

• Reinventing the Wheel: Scala’s built-in sorting methods (e.g., Array.sortWith or Array.sorted) are more optimized and should generally be preferred in production.

Optimizing the Code

For better performance, consider using Scala's built-in sorting functions:

val sortedArr = arr.sorted

This single line sorts the array efficiently using Scala’s optimized sorting algorithm.

Conclusion

While this custom sorting implementation is not optimized for large-scale use, it serves as a valuable educational exercise. By understanding and implementing basic algorithms like bubble sort, developers gain insights into how sorting works under the hood.

For more Scala tutorials and real-world use cases, visit orientalguru.co.in.