Switch in Perl

In Perl, switch is not a built-in control structure but can be implemented using given and when statements. Here’s an example of how switch can be used in Perl:

use feature 'switch';
my $score = 60;
given($score) {

   when($_ > 90) { print "Your grade is A\n"; }

   when($_ > 80) { print "Your grade is B\n"; }

   when($_ > 70) { print "Your grade is C\n"; }

   when($_ > 60) { print "Your grade is D\n"; }

   default { print "You failed the exam\n"; }

}

In this example, we determine the grade of a student based on their score. We start by using the given statement to give the value of $score to $_, which is the default variable for when statements. Then, we use a series of when statements to specify the conditions of each grade. Finally, we use the default statement to handle cases that don’t match any of the when conditions.

Another example:

use feature 'switch';
my $fruit = "banana";
given($fruit) {

   when("apple") { print "This is an apple\n"; }

   when("orange") { print "This is an orange\n"; }

   when("banana") { print "This is a banana\n"; }

   default { print "This is not an apple, orange, or banana\n"; }

}

In this example, we use a given statement to determine the type of fruit based on the value of $fruit. We then use a series of when statements to specify the conditions of each fruit. Finally, we use the default statement to handle cases that don’t match any of the when conditions.

It’s important to use the break statement to prevent multiple when statements from executing. The break statement is optional in Perl, but can be used to prevent fall-through of statements.