如何从给定的一组值生成 map 的随机值，然后将键和值存储到 Scala 中的单独变量中

Question

I am trying to generate the 1000 random key-val map pairs from the given(statically defined) 2 map key-val pairs in scala and also later i would want to break the key and value pairs and store them into separate variables

Whatever i have tried:

object methodTest extends App{

  val testMap = Map("3875835"->"ABCDE","316067107"->"EFGHI")
  def getRandomElement(seq: Map[String,String]): Map[String,String] = {

    seq(Random.nextInt(seq.length))
  } 
 var outList = List.empty[Map[String,String]]
 for(i<-0 to 1000){
   outList+=getRandomElement(testMap)
 }
 print(outList)
}

The Output should generate 1000 Key-val pairs of map like i am showing below

[3875835,ABCDE]
[316067107,EFGHI]
[3875835,ABCDE]
[316067107,EFGHI]
[316067107,EFGHI]
............
............
............. upto 1000 random key-val pairs

Please help me figure out where i am going wrong and let me know How to resolve it, if any issue regarding the requirement, please feel free to comment for it

Answer 1

You can transform your seed map testMap into sequence of key/value tuples using .toSeq and then generate key/value pairs by iterating over the list of numbers from 0 until 1000, associating each number to a random choice between first or second element of the seed:

import scala.util.Random

val testMap = Map("3875835" -> "ABCDE", "316067107" -> "EFGHI")

val seed = testMap.toSeq
val keyValuesList = (0 until 1000).map(index => seed(Random.nextInt(seed.size)))

Note: 0 until 1000 will return all the numbers from 0 to 1000 excluded, so 1000 numbers. If you use 0 to 1000 you will get all the numbers from 0 to 1000 included, so 1001 numbers.

If you want to print the resulting list, you can use .foreach method with println function as argument:

keyValuesList.foreach(println)

And you will get:

(3875835,ABCDE)
(316067107,EFGHI)
(3875835,ABCDE)
(3875835,ABCDE)
(316067107,EFGHI)
(3875835,ABCDE)
...

if you want to keep only the keys, you can iterate on the list using .map method, taking only the first element of the tuple by using ._1 method, that retrieve the first element of a tuple:

val keys = keyValuesList.map(keyValuePair => keyValuePair._1)

And if you want only a list containing all second elements of each pair:

val values = keyValuesList.map(keyValuePair => keyValuePair._2)