What are arrays in Scala?

In Scala, arrays are defined as special kinds of collections. We use these to store a fixed number of elements of the same data type.

Arrays in Scala are similar in syntax and mutability to arrays in other languages. However, Scala arrays may differ in functionality.

Scala supports both one-dimensional and multi-dimensional arrays. Since Scala arrays are very generic in nature, it is easy to declare them. Mostly, arrays just need an abstract parameter T for the datatype of the array.

1-Dimensional arrays

Let’s explore a 1D array in Scala.

Declaration

var arrayname = new Array[datatype](size)

var myarray = Array(12, 13, 15, 29, 34, 56, 21, 34)

Both of these declarations are valid to declare arrays in scala.

This declaration is very simple and follows the standard array declarations of other languages as far as syntax is concerned.

size is the total number of elements in the array. datatype refers to the type of array (Integer, String, Double, etc).

Code

The code below shows how to declare an array, access an individual array item, update an array item, and assign individual values at the required array indices.

object Main extends App {
    var myarray = Array(12, 13, 15, 29, 34, 56, 21, 34)
    // printing elements of array      
    println("Elements of array")
    for ( n <-myarray )
    {
        println(n)
    }
    // printing 4th array element
    println("element at index 4: " + myarray(4))
    // updating element at array index 4
    myarray(4) = 59
    // printing 4th array element
    println("element at index 4 after updating: " + myarray(4))
    // Creating a new array by specifying datatype and length
    // create a string array of 5 elements
    var cities = new Array[String](5)
        
    // Adding element in an array 
    cities(0)="Hong Kong"
    cities(1)="Tokyo"
    cities(2)="Islamabad"
    cities(3)="Cape Town"
    cities(4) = "New York"
    println("Displaying array: ")
        
    for ( city <-cities )
    {
        println(city)
    }
}

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