@noelrappin
On page xii of the Preface, the paragraph beginning with, “Here, you can see…,” has an error in the last sentence. Following the “em dash” in the last sentence, the text says, “you’d need to use a method such as puts have the values written to program output.” I believe there should be a “to” before the “have” like, “you’d need to to use a method such as puts to have the values written to program output.”