CODEWITHSUNDEEP
scalamapstuples
Sudipta Deb
Sudipta Deb

Reputation: 1050

Tuples in Scala not working as expected

Can you please help me in understanding the behaviour

  //Creating a tuple
  val myTuple = ("Sudipta","Deb","Switzerland",1234)
                                                  //> myTuple  : (String, String, String, Int) = (Sudipta,Deb,Switzerland,1234)
  myTuple._2                                      //> res0: String = Deb
  myTuple._4                                      //> res1: Int = 1234
  val (first, second, third, fourth) = myTuple    //> first  : String = Sudipta
                                                  //| second  : String = Deb
                                                  //| third  : String = Switzerland
                                                  //| fourth  : Int = 1234
  //val (first1, second1, _) = myTuple

Now last line is giving me the error:

constructor cannot be instantiated to expected type;  found   : (T1, T2, T3)  required: (String, String, String, Int)

My Question is why it is behaving like this? In the Scala for Impatient Book this is what is written:

You can use a _ if you don’t need all components:
val (first, second, _) = t

Just for your reference, if you want to see the full code, it is in my GitHub Repository. Link: Scala Worksheet

Upvotes: 1

Views: 359

Answers (1)

Boldizsár Németh
Boldizsár Németh

Reputation: 1847

You have to put one _ for every unused tuple member.

val (first1, second1, _, _) = myTuple

Upvotes: 3

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