Count how many times a string repeats itself SCALA - string

Question

Hi I´m trying to get the number of times an artist name repeats in some years for this I have this
var artists=Array.ofDim[String](994,2)//artist,year
var artists2=Array.ofDim[String](250)//artist name
var artists3 = Array.ofDim[Int](250)//number of times
And the user has to enter ano1 and ano2 that are the years margin we want
val loop = new Breaks;
for(i <- 0 to 993){//copiamos
loop.breakable{
for(j<- 0 to 249){
if(artists2(j).contentEquals("NULL") && artists(i)(1).toInt>=ano1 && artists(i)(1).toInt<=ano2){
artists2(j)=artists(i)(0)
artists3(j)= 1
loop.break;
}else if(artists(i)(0).contentEquals(artists2(j)) && artists(i)(1).toInt>=ano1 && artists(i)(1).toInt<=ano2){
artists3(j)= artists3(j)+1
loop.break;
}
}
}
}
println(artists2.mkString("\n"))
println(artists3.mkString(","))
For some reason my if doesnt work or j add itself 1 after entering in the if because every time is creating a new element in artists2 instead of adding it to artists3
The output I get is artists3 filled with 1 because for some reason it never checks the other part of the if

Answer 1

I'm sorry if this sounds a bit harsh, but there are so many things wrong with your code it's hard to know where to begin.
The main problems are 1) your code isn't very scala-like, and 2) you're using data structures and variable names designed to make things as difficult as possible to understand.
Here's a brief attempt to redesign things. It may not meet all your requirements but perhaps it will start you in a better direction.
val mockdata = List( ("Tom", 2001)
, ("Sue", 2002)
, ("Joe", 2002)
, ("Sue", 2005)
, ("Sue", 2004)
, ("Jil", 2001)
, ("Tom", 2005)
, ("Sue", 2002)
, ("Jil", 2012)
)
def countArtists( dataSet: List[(String,Int)]
, anoStart: Int , anoEnd: Int): Map[String,Int] = {
val artists = for {
(artist, year) <- dataSet
if year >= anoStart && year <= anoEnd
} yield artist
artists.distinct.map(name => name -> artists.count(_ == name)).toMap
}
val count2002to2011 = countArtists(mockdata, 2002, 2011)
At this point you can use the result to get interesting information.
scala> count2002to2011.keys // all artists within the time period
res0: Iterable[String] = Set(Sue, Joe, Tom)
scala> count2002to2011.values.sum // total count within the time period
res1: Int = 6
scala> count2002to2011("Sue") // count for just this artist
res2: Int = 4

Answer 2

your implementation seems a little bit confused, if i understood what you needed, i would like if i may, share how i would have implemented your research, in a more functionnal/scala and clear way.
case class Artist(name: String, year: Int)
case class ArtistNames(name: String)
case class ArtistResult(name: String, nbOccurence: Int)
val anno1 = 1950
val anno2 = 1960
def checkArtist(artists: Seq[Artist], artistNames: Seq[ArtistNames]): Seq[ArtistResult] = {
artists.map{ artist =>
def countOccurence(artist: Artist, artistNames: Seq[ArtistNames], occurence: Int): Int = {
artistNames match {
case Nil => occurence
case head :: tail =>
if (head.name == artist.name && artist.year >= anno1 && artist.year <= anno2) countOccurence(artist, tail, occurence + 1)
else countOccurence(artist, tail, occurence)
}
}
val occurrence = countOccurence(artist, artistNames, 0)
ArtistResult(artist.name, occurrence)
}
}
val artistResultList: Seq[ArtistResult] = checkArtist(/* insert your data here */)
i hope i answered a little bit your question.