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schwartz
Asked: 2020-10-12 04:40:07 +0800 CST 2020-10-12 04:40:07 +0800 CST

Function returns Anyval

  • 772

In Scala , why would such an expression return AnyVal? (I was expecting a boolean)

if (expr0)
    if ((expr1)&&(expr2))
        true
    else if (expr3)
        false
    else
        recFun(arg0, arg1)

Note 1: recFun is a recursive function...

Note 2: It is the last line of the recursive function itself...

scala

2 Answers

  1. Best Answer

    You are using an expression ifwith no part else, which is equivalent to:

    if (expr0)
    res_booleano // resultado del if anidado
else
   ()

    That is, when expr0 == false, the result of ifis (), of type Unit. In total, all of the ifends up having the type AnyVal, being the common supertypeBoolean of and Unit.

    • 0

  2. If performance is not a major problem, the best thing you can use for the problem you have is pattern matching, it gives you a much cleaner code.

    user.password == enteredPassword match {
   case true => println("User is authenticated")
   case false => println("Entered password is invalid")
}
    • -1