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scalanamed-parameters

How does Scala know what method to invoke ( named parameters )

class Algo { 
    def a(  a : String = "Hola ",  b : String  = "adios" ) {
        print( a )
        print( b )
    }
    def a() { 
        print ("Uh?")
    }
}
object Algo { 
    def main( args : Array[String] ) { 
        new Algo().a()
    }
}

prints Uh?

If method a() is not defined, the code prints "Hola adios" using the default values.

So, I deduce, from this, that, if an exact signature is match, that is preffered.

Is this reasoning correct?

Solution

  • This behavior is clearly defined in SID #1, section 3.1.

    Overloading Resolution In a method application expression, when multiple overloaded alternatives are applicable, the alternative which use default arguments is never selected.