scalatutorials

Collections · 28 of 42

Collections - Accessing Elements

  • You can access the elements of Arrays, Lists, Maps and Sets using ()
  • For Maps, accessing a key that doesn’t exist throws an exception: java.util.NoSuchElementException: key not found. To check if a key exists use map.contains(key), or use a default value: map.getOrElse(key, defaultValue)
val array = Array(1,2,3)
val list = List(1, 2, 3)
val map = Map("one" -> 1, "two" -> 2, "three" -> 3)
val set = Set("a","b","c")

//Accessing items
val arrayItem = array(0) //returns item at index 0 which is 1
val listItem = list(1) //returns item at index 1 which is 2
val mapItem = map("three") //returns 3
val setItem = set("a")  //returns true

println(arrayItem)
println(listItem)
println(mapItem)
println(setItem)

Contents

Scala basics

  1. Overview
  2. Scalculator
  3. Operators are methods
  4. Variables
  5. Final variables
  6. Printing values
  7. String interpolation
  8. String formatting
  9. Useful operations
  10. Method definition
  11. Method definition 2
  12. Method definition 3
  13. Anonymous functions
  14. Anonymous functions 2
  15. Return multiple values
  16. Declare multiple variables
  17. Assign multiple variables
  18. Loops using while
  19. Loops using for
  20. Loops without loops
  21. If
  22. Match as a switch
  23. Arrays
  24. Lists
  25. Sets
  26. Maps
  27. Mutable collections
  28. Collections: accessing elements
  29. Collections: concatenation
  30. Mutable collection operations
  31. Immutable collections with var
  32. Collections: useful methods
  33. Classes
  34. Classes, continued

What's new in Scala 3

  1. Scala 3: what changed
  2. Optional braces & new control syntax
  3. Top-level definitions & @main
  4. Enums & ADTs
  5. Extension methods
  6. given & using
  7. Union & intersection types
  8. Smaller niceties