Text & Regex

Perl Word Frequency Counter & Text Parser

Parse a multiline text block in Perl, sanitize tokens using regular expressions, and tally word frequencies using hashes.

Perl Source Code

Editable code sample with line numbers

Perl

Expected Output

When this program is compiled and executed, the terminal outputs:

Word Frequencies (Descending):
  code         : 3
  zencompiler  : 2
  and          : 1
  compile      : 1
  compilers    : 1
  fast         : 1
  instantly    : 1
  provides     : 1
  test         : 1
  with         : 1
  write        : 1

How the Code Works

Perl excels at text processing with built-in regular expression match loops ($text =~ /\b.../g) and hash tables (%counts) for counting unique tokens.

Time Complexity

O(N log N)

Space Complexity

O(N)

Key Takeaways & Best Practices

Perl hashes (%name) store key-value pairs with O(1) average lookup.
sort { $counts{$b} <=> $counts{$a} } provides custom comparator sort order.

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