Question

So I assume my issue has to do with what is going on under the hood, but I don’t understand why this doesn’t works:

scala> b = b :: "apple";
<console>:8: error: value :: is not a member of java.lang.String

but this does:

scala> b = "apple" :: b;
b: List[java.lang.String] = List(apple, pear)

Thanks.

Answer 1

Method names that end in : are right associative, so b :: "apple" tries to call the :: method on a String, which doesn’t exist.

The normal strategy for appending things if you must use a List is to add things to the beginning then reverse the result when you’re done. But as Rex says, using a Vector might be better.