Scala | Repeated Method Parameters

In Scala, Repeated Method parameters are supported, which is helpful when we don’t know the number of arguments a method requires. This property of Scala is utilized in passing limitless parameters to a method defined.
Important points :

• The methods with Repeated Parameters should have each of the parameters of same type.
• A Repeated parameter is always the last parameter of the method defined.
• The method defined by us, can have only one parameter as Repeated Parameters.

Example:

// Scala program of repeated
// parameters

// Creating object
object repeated
{

    // Main method
    def main(args: Array[String])
    {

        // Creating a method with
        // repeated parameters
        def add(x: Int*)
        : Int =
        {

            // Applying 'fold' method to
            // perform binary operation
            x.fold(0)(_+_)

        }

        // Displays Addition
        println(add(2, 3, 5, 9, 6, 10, 11, 12))
    }
}

Output:

58

In order to add any number of extra parameters, we need to put * mark after the type of the parameter being used.
Some more examples of Repeated Parameters:

• An Array can be passed in the Repeated Parameter method.
  Example:

  // Scala program of repeated
  // parameters
  
  // Creating object
  object arr
  {
  
      // Main method
      def main(args: Array[String])
      {
  
          // Creating a method with
          // repeated parameters
          def mul(x: Int*)
          : Int =
          {
  
              // Applying 'product' method to
              // perform multiplication
              x.product
  
          }
  
          // Displays product
          println(mul(Array(7, 3, 2, 10): _*))
      }
  }
  Output:

  420
  

  In order to pass an array in the defined method, we need to put a colon i.e, : and _* mark after passing the values in the array.

• An example to show that Repeated Parameters are always the last parameter of the method defined.
  Example:

  // Scala program of repeated
  // parameters
  
  // Creating object
  object str
  {
  
      // Main method
      def main(args: Array[String])
      {
  
          // Creating a method with
          // repeated parameters
          def show(x: String, y: Any*) =
          {
  
              // using 'mkString' method to
              // convert a collection to a
              // string with a separator
              "%s is a %s".format(x, y.mkString("_"))
          }
  
          // Displays string
          println(show("GeeksforGeeks", "Computer",
                              "Sciecne", "Portal"))
      }
  }
  Output:

  GeeksforGeeks is a Computer_Sciecne_Portal
  

  Here, format is used to format strings.