In a Scala 3 project, I have a method which returns a Try from a given String def translate(text: String) : Try[Thing] = … and a method which is supposed to read the contents of a file and pass it on to the first method. Here, I want to use Using because as far as… Read More Scala 3 Using – problems when reading from file

I want to build a map however I want to discard all keys with empty values as shown below: @tailrec def safeFiltersMap( map: Map[String, String], accumulator: Map[String,String] = Map.empty): Map[String, String] = { if(map.isEmpty) return accumulator val curr = map.head val (key, value) = curr safeFiltersMap( map.tail, if(value.nonEmpty) accumulator + (key->value) else accumulator ) }… Read More Extend / Replicate Scala collections syntax to create your own collection?

I’m new to Scala, actually learning it. I’m trying to combine multiple Lists and print a table by passing the list into a function. However when I try referencing values by index I get the error Serializable does not take parameters println("%3s%3s%3s\n".formatted(elm(0),elm(1),elm(2))) val list1 = List("1","2","3") val list2 = List("1","1","5") var newLst = List[Serializable]() newLst… Read More In Scala how do you reference index in List of Serializable?

I have a Case Class User and I want to return it as Future(User). But when I do the same I get this error: No implicits found for parameter executor: ExecutionContext Can someone help me with the right syntax to convert a non future result to future return type? >Solution : If you don’t define… Read More Scala Convert a Variable to Future?

Does scala provide a default apply method for a class? I have a class: class Player(tea: String, sal: Int = 0) { val team = tea private val salary = sal } So no apply method here, and I haven’t defined any companion object for it, so no apply method from there too. But I… Read More scala: Any default apply method in a class?

I want to run parameterized mean on a List, however it throws a compile error: def mean[A](xs: Seq[A])(implicit num: Numeric[A]): Option[A] = { import num._ if (xs.isEmpty) None else Some(xs.sum / xs.size) } cmd11.sc:4: value / is not a member of type parameter A else Some(xs.sum / xs.size) ^Compilation Failed What’s wrong with this approach?… Read More Parameterized mean not working as expected

def checkHappynumber(n: Int): Boolean = { val set = scala.collection.mutable.HashSet[Int]() var num: Int = n while(num != 1) { var newnum: Int = 0 while (num != 0) { newnum += (num % 10) * (num % 10) num /= 10 } if(!set.add(newnum)){ return false; } num = newnum } return true } What’s "!"… Read More what is "!" means in this function?

I have two string dates a = ‘2021-05-23 b = ‘2021-04-24" I’m trying to define a function that compares two string dates and returns true if b is one month greater than a. Can anyone help me? Thanks >Solution : The question is a little bit unclear, like do you mean the difference would be… Read More How to compare string dates in scala without converting it into date type

I have array contain string items in scala , each item contain from prefix + || + double value like below : var y = Array("Zara||6.0", "Nuha||4.0","Zara||2.0","Zara||0.1") what I want to Do : i need sum all double value from above array (y(i).split("\|\|")(1)) But if the prefix the duplicated in the array then I only… Read More how to sum only the max value for common prefix inside the array in scala