This topic is about Scala Collections – Seq.
Scala Seq is a trait to represent immutable sequences. This structure provides index based access and various utility methods to find elements, their occurences and subsequences. A Seq maintains the insertion order.
Declaring Seq Variables
The following is the syntax for declaring an Seq variable.
Syntax
val seq: Seq[Int] = Seq(1, 2, 3, 4, 5)
Here, seq is declared as an Seq of numbers. Seq provides commands like the following −
Command
val isPresent = seq.contains(4); val contains = seq.endsWith(Seq(4,5)); var lastIndexOf = seq.lasIndexOf(5);
Processing Seq
Below is an example program of showing how to create, initialize and process Seq −
Example
import scala.collection.immutable.Seq
object Demo {
def main(args: Array[String]) = {
var seq = Seq(1, 2, 3, 4, 5, 3)
// Print seq elements
seq.foreach{(element:Int) => print(element + " ")}
println()
println("Seq ends with (5,3): " + seq.endsWith(Seq(5, 3)))
println("Seq contains 4: " + seq.contains(4))
println("Last index of 3: " + seq.lastIndexOf(3))
println("Reversed Seq" + seq.reverse)
}
}
Save the above program in Demo.scala. The following commands are used to compile and execute this program.
Command
\>scalac Demo.scala \>scala Demo
Output
1 2 3 4 5 3 Seq ends with (5,3): true Seq contains 4: true Last index of 3: 5 Reversed SeqList(3, 5, 4, 3, 2, 1)
In this topic we learned about Scala Collections – Seq. To know more, Click Here.