Array item used for fix length array in Scala. array of integers initialized by 0, while array of string initialized with null. we should use () to access the elements of Array.

val nums = new Array[Int](10)

val s = Array("Hello", "World")

s(0) = "Goodbye" // this is equivalent to s.update(0,"Goodbye") as all oparations are method call in scala

In Scala ArrayBufferused for variable length array. which is implemented inscala.collection.mutable.ArrayBuffer

val b = ArrayBuffer[Int]()

// Or new ArrayBuffer[Int]

This will create an empty Array buffer, in which we can add Integers.

to add elements :

b+ = (1,2,3,4)

b.insert(2, 6)

//insert before index 2.

We can also use insertor removeto add/delete.

*Yield : The for (...) yield loop creates a new collection of the same type as the original
collection.

*guard : an if inside the
for.To process the elements from an Array which match the particular conditions.

for (elem <- a if a % 2 == 0) yield 2 * elem

On Arrays you can directly use sum, min, max, sorted methods.

Multidimensional Arrays

As in Java, Scala also supports multidimensional array as arrays of arrays.

val matrix = Array.ofDim[Double](3, 4) //Array of three rows, four columns of Double type.

To access the element :

matrix(row)(column)

Scala arrays are implemented as Java arrays, you can pass them back and
forth between Java and Scala.

Tuple

Tuples are also immutable like list, but it can contains elements of different types. so a List can be either List[Int] or List[String], while tuple can be combination of both. So mostly in Java we used JavaBean like class to hold multiple return values, while in scala we can do that by using tuples.

val pair = (99, "Luftballons") // to create and initilized tuple of type Tuple2[Int, String] i.e. Tuple of length 2, we just need to place the objects into parenthesis seprated by commas

println(pair._1)//to access the elements of tuple you can use ._and index of element in tuple.

println(pair._2)

The type of ('u', 'r', "the", 1, 4, "me") is
Tuple6[Char, Char, String, Int, Int, String]. Although conceptually you could create tuples of any length, currently the Scala library
only defines them up to Tuple22 .

*Note : you can not use pair(0) to access the element of tuple same as list, because that call apply method, and apply always return same type of element, while tuples support elements of diffrent type.