scalaapache-sparkforeachrddscala-ide

How to use Scala format and substitution interpolation together?

I am new to scala and spark and have a requirement where i want to use both format and substitution in a single println statement.

Here is the code:

val results = minTempRdd.collect()

for(result <- results.sorted){
  val station = result._1
  val temp = result._2
  println(f" StId $station Temp $temp%.2f F")
}

where results is an RDD having structure (stationId, Temperature).

Now i want to convert this code into one liner. I tried the following code:

val results = minTempRdd.collect()

results.foreach(x => println(" stId "+x._1+" temp = "+x._2))

It works fine, but i am not able to format the second value in tuple here.

Any suggestions, how can we achieve this?

Solution

  • The first way is to use curly brackets inside interpolation, which allow to pass arbitrary expressions instead of variables:

    println(f" StId ${result._1} Temp ${result._2}%.2fF")

    The second way is to unpack the tuple:

    for ((station, temp) <- results.sorted) 
  println(f" StId $station Temp $temp%.2fF")

    Or:

    results.sorted.foreach { case (station, temp) => 
  println(" stId "+x._1+" temp = "+x._2) 
}