What is the keys() function in Perl?

Overview

In Perl, the keys() function is used to return all the keys of a hash as a list.

Syntax

keys(hash)

Parameters

This function takes the parameter hash. This is the hash we want to get the keys of.

Return value

It returns a list of keys.

Example

# create hashes
%hash1 = ('One' => 1,
         'Two' => 2,
         'Third' => 3,
         'Fourth' => 4);
  
%hash2 = ('Edpresso' => 1,
         'Is' => 2,
         'Awesome' => 3);
  
# get keys
@keys1 = keys(%hash1);
@keys2 = keys(%hash2);
# print keys
print("Keys are ", join("-", @keys1), "\n");
print("Keys are ", join("-", @keys2), "\n");

Explanation

  • Line 2–9: We create hashes.
  • Line 12 and 13: We use the keys() function to get the keys of the hashes.
  • Line 16 and 17: We use the join() method to separate the keys of the hashes that the key() function returned.

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