Char or String -> Unicode value in Scala?

Question

So I'm working through a few of the exercises in "Scala for the Impatient" and one of them is:

Write a for loop for computing the product of the Unicode codes of all letters in a string. For example, the product of the characters in "Hello" is 9415087488 L.

The next problem is to do the same, but without a for loop - it hints that we should check StringOps in Scaladoc.

I checked the RichChar and StringOps section in Scaladoc, and perhaps I'm misreading or looking in the wrong places, but I can't find anything that gets me to match their output. I've thus far tried:

scala> x.foldLeft(1)(_ * _.toInt) res0: Int = 825152896  scala> x.foldLeft(1)(_ * _.getNumericValue) res5: Int = 2518992  scala> x.foldLeft(1)(_ * _.intValue()) res6: Int = 825152896  scala> var x = 1 x: Int = 1  scala> for (c <- "Hello") x *= c.toInt  scala> x res12: Int = 825152896 

Which does not match their output.

How do I do this, in both the for and non-for way?

Thanks!

Answer 1

When you do x.foldLeft(1)(_ * _.toInt), the result type will be inference to an Int, but 9415087488 is too large for an Int to store it.

So you need to tell Scala using Long to store it.

scala> val x = "Hello" x: java.lang.String = Hello  scala> x.foldLeft(1L)(_ * _.toInt) res1: Long = 9415087488  scala> var x: Long = 1 x: Long = 1  scala> for (c <- "Hello") x *= c.toInt  scala> x res7: Long = 9415087488