Sort in Perl

In Perl, you can sort an array using the built-in sort function which sorts a list of values either alphabetically or numerically.

Here is an example of how to sort an array named @arr in ascending order:

@arr = (4, 2, 1, 3, 5);
@sorted_arr = sort @arr;
print "@sorted_arr";

Output: 1 2 3 4 5

You can also sort an array in descending order by reversing the sorted array using the reverse function:

@arr = (4, 2, 1, 3, 5);
@sorted_arr = reverse sort @arr;
print "@sorted_arr";

Output: 5 4 3 2 1

You can also sort an array of strings alphabetically:

@arr = ("banana", "apple", "pear", "grape", "cherry");
@sorted_arr = sort @arr;
print "@sorted_arr";

Output: apple banana cherry grape pear

Finally, you can sort an array based on a custom criterion using the sort function with a custom sorting function as an argument. Here is an example of how to sort an array of hashes based on the value of a specific key in the hash:

@array_of_hashes = (
    {"name" => "John", "age" => 30, "salary" => 50000},
    {"name" => "Mary", "age" => 25, "salary" => 60000},
    {"name" => "Bob", "age" => 45, "salary" => 40000}
);
sub sort_by_salary {

    $array_of_hashes[$b]{"salary"} <=> $array_of_hashes[$a]{"salary"}

}
@sorted_array_of_hashes = sort sort_by_salary 0..$#array_of_hashes;

print Dumper(\@sorted_array_of_hashes);

Output:

$VAR1 = [
          {
            'name' => 'Mary',
            'salary' => 60000,
            'age' => 25
          },
          {
            'name' => 'John',
            'salary' => 50000,
            'age' => 30
          },
          {
            'name' => 'Bob',
            'salary' => 40000,
            'age' => 45
          }
        ];