Scala | Repeated Method Parameters

Last Updated : 29 Mar, 2019

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

// 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:

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

// 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:

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

// 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.

Scala | Named Arguments

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