I’ve started going through the book: Scala for the Impatient by Cay Horstmann. I’m posting the solution to chapter 2 exercises below.
Advertisements
I’ve started going through the book: Scala for the Impatient by Cay Horstmann. I’m posting the solution to chapter 2 exercises below.
This is good, but all the “Hello” exercises should use longs instead of ints, the correct product being 9415087488.
Hi, yeah thanks for pointing this out. The correct product is 9415087488! Therefore, long type has to be used 🙂
Wouldn’t it be even better to use BigInt type? Replacing “Hello” by a longer sentence, the function above fails to give a correct answer, doesn’t it?
Hi Yrg. Yes, you are right. BigInt is the best choice.
Nice work. I think the answer to exercise 5 is wrong. A procedure doesn’t return anything and hence it shall be without an ‘=’:
def countDown( num: Int ) { for(i <- num to (0, -1)) println(i) }
It is either without ‘=’ or returntype Unit with =.
The type of the function is Unit implicitly. However, I agree that it’s better to explicitly mention the Unit type. I’ve updated the code accordingly.
Personally, I prefer not to omit the ‘=’ for procedures. I find it easier to stick to a consistent style of always using ‘=’ when defining functions and methods.
answer to 10 is wrong as well!
your solution doesn’t work if we call xpown(2, -1)
Thanks for pointing out the problem. I’ve revised the code to use BigDecimal instead of BigInt.
xpown function always returns 0 here if n is negative, which is not correct.
Thanks for pointing out the problem. I’ve revised the code to use BigDecimal instead of BigInt.