Question

How to convert an array of digits to a number in Scala

Answer 1

object Main extends App {
  def intArrayToIntNumber(arr: Array[Int]): Int = {
    var n = 0

    for (num <- arr) {
      n = n * 10 + num
    }

    n
  }

  val arr = Array(4, 6, 3, 9, 1, 2)
  
  println(intArrayToIntNumber(arr))
}


  
  
/*
run:
    
463912
  
*/

 

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Answer 2

object Main extends App {
  val arr = Array(4, 6, 3, 9, 1, 2)
  
  val number = arr.mkString("").toInt
  
  println(number)  
}


  
  
/*
run:
    
463912
  
*/

 

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Answer 3

object Main extends App {
  val arr = Array(4, 6, 3, 9, 1, 2)
  
  val number = arr.reduceLeft((acc, digit) => acc * 10 + digit)
  
  println(number)  
}


  
  
/*
run:
    
463912
  
*/

 

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Answer 4

object Main extends App {
  val arr = Array(4, 6, 3, 9, 1, 2)
  
  val number = arr.foldLeft(0)((acc, digit) => acc * 10 + digit)
  
  println(number)  
}


  
  
/*
run:
    
463912
  
*/

 

70+ SQL courses for beginners and professionals