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Perl 6 Deep Dive

You're reading from   Perl 6 Deep Dive Data manipulation, concurrency, functional programming, and more

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Product type Paperback
Published in Sep 2017
Publisher Packt
ISBN-13 9781787282049
Length 402 pages
Edition 1st Edition
Languages
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Author (1):
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Andrew Shitov Andrew Shitov
Author Profile Icon Andrew Shitov
Andrew Shitov
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Table of Contents (15) Chapters Close

1. What is Perl 6? FREE CHAPTER 2. Writing Code 3. Working with Variables and Built-in Data Types 4. Working with Operators 5. Control Flow 6. Subroutines 7. Modules 8. Object-Oriented Programming 9. Input and Output 10. Working with Exceptions 11. Regexes 12. Grammars 13. Concurrent Programming 14. Functional Programming 15. Reactive Programming

Understanding code blocks and variable scoping

In the previous chapter, we discussed variables, which are named entities that you use in a program. As in many programming languages, in Perl 6, the names are visible inside their scope and not outside of it.

Take, for instance, a simple program, where the $name variable is only used once, as follows:

my $name = 'Mark';
say "Hello, $name!";

The variable can be reused after it is used in printing the greeting:

my $name = 'Mark';
say "Hello, $name!";

$name = 'Carl';
say "Hello, $name!";

This works because both the printing statements are located in the same scope and the $name variable is visible there.

A block in Perl 6 is a piece of code that is located inside a pair of curly braces. A block creates its own scope. Thus, a variable declared in a block is only visible inside...

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