三元运算符无法正常运行

Question

I'm trying to make a ternary operator in scala but actually it seems that the '?' character cannot be resolved

here is the completed method

object Credit {
  def getMaximumWeek(orderId: Int, locale: String): Int = {
    val orderCompletedHistoryCount = Order.getOrderCompletedHistoryCount(orderId, locale);
   orderCompletedHistoryCount == 0 ? 0: Order.getMaximumAllowedWeeks(orderId, locale)
  }
}

referenced to this link , I'm getting an error connot resolve symbol '?' even both method are returning integers

Answer 1

Scala does not have a ternary operator , like the ? operator C++ has for example, so the error is expected, regardless of what the two operadans return.

Use an if-else expression instead, like this:

if(orderCompletedHistoryCount == 0)
    0
else
    Order.getMaximumAllowedWeeks(orderId, locale)

Answer 2

You can use Scalaz for that. The only difference is it requires | sign instead of : sign.

import scalaz.Scalaz._

false ? "Yes" | "No" // returns No

It's not only for booleans, you can try it with Option objects as well:

None ? "Defined" | "Empty" // returns Empty

You should add the following line to build.sbt in order to use it:

libraryDependencies += "org.scalaz" %% "scalaz-core" % "7.2.16"