I am trying to use Ordering[T] with multiple types.
case class Person(name: String, age: Int)
Person("Alice", 20)
Person("Bob", 40)
Person("Charlie", 30)
object PersonOrdering extends Ordering[Person] {
def compare(a:Person, b:Person) =
a.age compare b.age
}
How do I sort by both name and age?
The collection needs to remain sorted with updates.
Order by the tuple of name and age.
Also, it's generally easier to call Ordering.by rather than extend Ordering yourself.
case class Person(name: String, age: Int)
implicit val personOrdering: Ordering[Person] =
Ordering.by(p => (p.name, p.age))
Seq(Person("a", 2), Person("b", 1), Person("a", 1)).sorted
// Seq[Person] = List(Person(a,1), Person(a,2), Person(b,1))
You can make a tuple and sort that:
val people = List(
Person("Alice", 20),
Person("Bob", 40),
Person("Charlie", 30)
)
people.orderBy(x => (x.name,x.age))
In case of extending Ordering should be the same, make a tuple and compare them
