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Mastering Modern Perl: Writing Efficient and Maintainable Code

Branching Directives: if, unless, else, elsif

Explore the use of Perl's branching directives such as if, unless, else, and elsif to control program execution flow. Understand when and how to apply these conditionals effectively to write maintainable and readable Perl code by managing true and false expressions and handling multiple exclusive cases.

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Control flow directives

Perl’s basic control flow is straightforward. Program execution starts at the beginning (the first line of the file executed) and continues to the end:

Perl
say 'At start';
say 'In middle';
say 'At end';

Perl’s control flow directives change the order of what happens next in the program.

Branching directives

Branching directives in Perl are explained below:

The if directive

The if directive performs the associated action only when its conditional expression evaluates to a true value:

Perl
my $name = 'Bob';
say 'Hello, Bob!' if $name eq 'Bob';

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