Scala Collections - ArrayBuffer

Array in Scala is homogeneous and alterable, i.e it contains components of a similar data type and its components can change however the size of array can't change. To make an mutable, indexed sequence whose size can change ArrayBuffer class is utilized. To utilize, ArrayBuffer, scala.collection.mutable.ArrayBuffer class is imported, a instance of ArrayBuffer is created.

An ArrayBuffer is an Array of components, as well as the store's present size of the array. At the point when a element is added to an ArrayBuffer, this size is checked. if suppose the underlying array isn't full, the element is straightforwardly added to the array. and if the underlying array is full then a another large array is created and all the elements are copied into it.

An ArrayBuffer in Scala is a mutable, resizable collection that provides efficient sequential access to elements. It is part of the mutable sequence collections in Scala and is implemented using an array internally. Unlike fixed-size arrays, an ArrayBuffer can grow or shrink dynamically, allowing for flexible manipulation of elements without needing to predefine the size.

To use an ArrayBuffer, you first import scala.collection.mutable.ArrayBuffer and then instantiate it with elements. You can add elements to the end of an ArrayBuffer using the += operator or append multiple elements with the ++= operator. Elements can also be removed using the -=, --=, or remove methods.

Example:

var name = new ArrayBuffer[datatype]()  // empty buffer is created

var name = new ArrayBuffer("Mark", "prwa", "prwatech")

Use case 1:

Creating instance of ArrayBuffer:

import scala.collection.mutable.ArrayBuffer
object prwatech {
  def main(args: Array[String])
{
    // Instance of ArrayBuffer is created
    var name = ArrayBuffer[String]() 
    name += "Prwatech"
    name += "Data Science"
    name += "Big Data"
    println(name)
}
}


Output 
ArrayBuffer(Prwatech, Data Science, Big Data)

Use case 2:

Access element from ArrayBuffer

// Scala program to access element of ArrayBuffer

import scala.collection.mutable.ArrayBuffer
// Creating Object
object GFG
{
// Main Method
def main(args: Array[String])
{
// Instance of ArrayBuffer is created
var name = ArrayBuffer[String]()
name += "Prwatech"
name += "Data Science"
name += "Big Data"

// accessing 1th index element of arraybuffer
println(name(1)) 
}
}

Output:
Data Science

Use case 3:

Deleting ArrayBuffer Elements:

import scala.collection.mutable.ArrayBuffer
// Creating Object
object Prwatech 
// Main Method
def main(args: Array[String])
{
    // Instance of ArrayBuffer is created
    var name = ArrayBuffer( "Prwatech","Data Science","Big 
data","Machine Learning","Linux","MySql" ) 
   // deletes one element
   name -= "Prwatech"     
    
   // deletes two or more elements 
   name -= ("Linux", "Machine Learning")

   // printing resultant arraybuffer
   println(name) 
 }
}

Output:
ArrayBuffer(Data Science, Big data, MySql)

Scala Collections - ArrayBuffer