Menu
In Scala 2.8 is there a way to overload constructors of a case class?
If yes, please put a snippet to explain, if not, please explain why?
704
Constructors can be overloaded in a similar way as function overloading. Overloaded constructors have the same name (name of the class) but the different number of arguments. Depending upon the number and type of arguments passed, the corresponding constructor is called.
The answer is simple: Case Class can extend another Class, trait or Abstract Class. Create an abstract class which encapsulates the common behavior used by all the classes inheriting the abstract class.
Case Classes You can construct them without using new. case classes automatically have equality and nice toString methods based on the constructor arguments. case classes can have methods just like normal classes.
Overloading constructors isn't special for case classes:
case class Foo(bar: Int, baz: Int) { def this(bar: Int) = this(bar, 0) } new Foo(1, 2) new Foo(1) However, you may like to also overload the apply method in the companion object, which is called when you omit new.
object Foo { def apply(bar: Int) = new Foo(bar) } Foo(1, 2) Foo(1) In Scala 2.8, named and default parameters can often be used instead of overloading.
case class Baz(bar: Int, baz: Int = 0) new Baz(1) Baz(1) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
