Book Image

Perl 6 Deep Dive

By : Andrew Shitov
Book Image

Perl 6 Deep Dive

By: Andrew Shitov

Overview of this book

Perl is a family of high-level, general-purpose, interpreted, dynamic programming languages consisting of Perl 5 and Perl 6. Perl 6 helps developers write concise and declarative code that is easy to maintain. This book is an end-to-end guide that will help non-Perl developers get to grips with the language and use it to solve real-world problems. Beginning with a brief introduction to Perl 6, the first module in the book will teach you how to write and execute basic programs. The second module delves into language constructs, where you will learn about the built-in data types, variables, operators, modules, subroutines, and so on available in Perl 6. Here the book also delves deeply into data manipulation (for example, strings and text files) and you will learn how to create safe and correct Perl 6 modules. You will learn to create software in Perl by following the Object Oriented Paradigm. The final module explains in detail the incredible concurrency support provided by Perl 6. Here you will also learn about regexes, functional programming, and reactive programming in Perl 6. By the end of the book, with the help of a number of examples that you can follow and immediately run, modify, and use in practice, you will be fully conversant with the benefits of Perl 6.
Table of Contents (15 chapters)

Conditional checks

Taking decisions based on conditions is one of the fundamental needs in programming. The if keyword changes the flow of the program, depending on the result of a Boolean test. Considering the following code:

my $x = 5;
if $x < 10 {
say "$x < 10"; # 5 < 10
}

In this example, you can see the syntax used with the if keyword. The keyword is followed by a Boolean condition $x < 10, followed by the block of code in the curly braces. Unlike Perl 5, parentheses around the condition are not necessary.

The block of code is only executed if the condition evaluates to True.

The if statement can be accomplished by the else branch, which will take control when the condition is False:

my $x = 11;
if $x < 10 {
say "$x < 10";
}
else {
say "$x >= 10"; # 11 >= 10
}

With the given value of $x, the program executes the code...