Think Perl 6

Appendix A. Solutions to the Exercises

This (long) chapter provides solutions to the exercises suggested in the main matter of this book. However, it contains much more than that.

First, in many cases, it provides several different solutions, illustrating different approaches to a problem, discussing their respective merits or drawbacks and often showing solutions that may be more efficient than others.

Second, it often provides a lot of additional information or complementary examples.

Just the sheer volume of code examples of this chapter is likely to teach you a lot about programming in general and about the Perl 6 language in particular.

Finally, this chapter sometimes introduces (with examples) new concepts that are covered only in later chapters of the book. Having seen such examples may help you to get a smoother grasp to these new ideas when you get to these chapters. In a few cases, this chapter covers or introduces notions that will not be covered anywhere else in the book.

When you solve an exercise, even if you’re confident that you did it successfully, please make sure to consult the solutions in this chapter and to try them: you’re likely to learn quite a bit from them.

Exercises of Chapter 3: Functions and Subroutines

Exercise 3-1: Subroutine right-justify

The aim is to write a subroutine that prints a string with enough leading spaces so that the last letter of the string is in column 70 of the display.

This is the first real exercise of this book, so let’s do it step ...