Is it possible to have tuple assignment to variables in Scala? [duplicate]

by

This isn’t simply “multiple variable assignment”, it’s fully-featured pattern matching!

So the following are all valid:

val (a, b) = (1, 2)
val Array(a, b) = Array(1, 2)
val h :: t = List(1, 2)
val List(a, Some(b)) = List(1, Option(2))

This is the way that pattern matching works, it’ll de-construct something into smaller parts, and bind those parts to new names. As specified, pattern matching won’t bind to pre-existing references, you’d have to do this yourself.

var x: Int = _
var y: Int = _

val (a, b) = (1, 2)
x = a
y = b

// or

(1,2) match {
  case (a,b) => x = a; y = b
  case _ =>
}

More Related Contents:

  1. Why and how is Scala treating a tuple specially when calling a one arg function?
  2. Is there way to create tuple from list(without codegeneration)?
  3. Use functional combinators on Scala Tuples?
  4. Are HLists nothing more than a convoluted way of writing tuples?
  5. scala tuple unpacking
  6. Scala: Write a function to swap a number in place without using temporary variables
  7. What is the eta expansion in Scala?
  8. Understanding implicit in Scala
  9. Composing Option with List in for-comprehension gives type mismatch depending on order
  10. NullPointerException in Scala Spark, appears to be caused be collection type?
  11. Functions vs methods in Scala
  12. What does setMaster `local[*]` mean in spark?
  13. How to split a dataframe into dataframes with same column values?
  14. How to use regex to include/exclude some input files in sc.textFile?
  15. Valid identifier characters in Scala
  16. How to find spark RDD/Dataframe size?
  17. When to use parenthesis in Scala infix notation
  18. Stream vs Views vs Iterators
  19. Run custom task automatically before/after standard task
  20. What’s the easiest way to use reify (get an AST of) an expression in Scala?
  21. How to force IntelliJ IDEA to reload dependencies from build.sbt after they changed?
  22. Doing something before or after all Scalatest tests
  23. Scala : fold vs foldLeft
  24. Update operations on a Scala Case Class
  25. Provide schema while reading csv file as a dataframe in Scala Spark
  26. Difference between Iterator and Stream in Scala?
  27. Error with varargs for function-objects in Scala?
  28. Equivalent to Ruby’s #tap method in Scala [duplicate]
  29. How to split a sequence into two pieces by predicate?
  30. Spark – Error “A master URL must be set in your configuration” when submitting an app

Leave a Comment