As you can see in this example I have three different data types. It doesn't have any different name in Scala so an element that has two values is called a tuple and an element that has 22 values is still called a tuple. A simple example: val idUsername (0, randomusername) println(Id is: +. So let's create one that has three values. En Scala, una tupla es un valor que contiene un número fijo de elementos, cada uno de ellos puede ser de distinto tipo. A tuple in Scala is an immutable sequence of values of multiple types. And a tuple can contain, like I said two to 22 different values.
So I'm going to declare it as a val and I'll call it v is equal to. I'm going to delete the print line statement. The following is an example of a tuple holding an integer, a string, and the console. Unlike an array or list, a tuple can hold objects with different types but they are also immutable. And I'm just going to call it tuple examples. Scala tuple combines a fixed number of items together so that they can be passed around as a whole. I'm going to right click on my SRC package and go to new Scala worksheet. Let's create a worksheet so we can take a look at some tuples. The maximum number of miscellaneous elements that a tuple can have is twenty-two. The Scala tuples are immutable, i.e the objects of different type can be stored in the tuple but the value of these objects cannot be changed. The elements of Scala tuples may or may not be the same data type. Tuples can actually be created with anywhere from two to 22 values inside parentheses. A tuple is a data structure that has multiple elements.
In Scala we have a term for this type of pairing. These restrictions apply for any higher-order-function applied to a collection of tuples.- When working with a map collection we saw that each element in the map was a key value pair. The other option is to use a case statement to unpack the tuples using pattern matching: scala> l.map The first is to use the positional accessors _1 and _2: scala> l.map(e => e._1 + e._2) Scala cannot implicitly unpack the tuples in this manner.
However this results in the following error: :9: error: type mismatch It may seem natural to add the elements together using implicit tuple-unpacking: scala> l.map((e1: Int, e2: Int) => e1 + e2) For example, given the following list of tuples: scala> val l = List(1 -> 2, 2 -> 3, 3 -> 4) Tuples are often used within collections but they must be handled in a specific way. Create a tuple by enclosing the desired elements between parentheses. Solution A tuple gives you a way to store a group of heterogeneous items in a container, which is useful in many situations. The syntax for the pair in the map is the arrow syntax, making it clear that 1 is the key and a is the value associated with that key. When writing a Scala application, you want to create a small collection of heterogeneous elements. The arrow syntax for creating tuples of size two is primarily used in Maps, which are collections of (key -> value) pairs: scala> val m = Map(2 -> "world") More elegantly, you can use tuple extractors. For instance, we can use x._1 to access the first element of the x tuple. Scala> val z = 3 → "foo" //example of using U+2192 RIGHTWARD ARROW For tuples of size 2 (also called a 'pair') there's an arrow syntax.
A tuple can be defined using parentheses. Creating a new TupleĪ tuple is a heterogeneous collection of two to twenty-two values. This arbitrary limit was decided by language designers.Ī Tuple0 is equivalent to a Unit. The compiler has access to Tuple1 through Tuple22. Tuples are rewritten as objects by the compiler. Single Abstract Method Types (SAM Types).
0 kommentar(er)
