Word frequency in Ruby

A complete script: scan text, count words, print a ranked table.

#!/usr/bin/env ruby
# Count word frequencies in a small corpus and print a top-five table.

TEXT = <<~PROSE
  the quick brown fox jumps over the lazy dog
  the dog barks and the fox runs
  quick thinking wins the day
PROSE

counts = Hash.new(0)
TEXT.scan(/[a-z]+/) { |word| counts[word] += 1 }

widest = counts.keys.map(&:length).max
top = counts.sort_by { |word, n| [-n, word] }.first(5)

top.each do |word, n|
  bar = "#" * n
  puts format("%-#{widest}s %2d %s", word, n, bar)
end

puts "#{counts.size} distinct words, #{counts.values.sum} total"

How it works

1. scan walks every word match and feeds a Hash.new(0) counter.
2. sort_by with [-n, word] ranks by count, then alphabetically.
3. format pads columns so the histogram bars line up.

Keywords and builtins used here

• do
• end
• format
• puts

The run, in numbers

Lines

21

Characters to type

538

Tokens

124

Three-star pace

80 tpm

At the three-star pace of 80 tokens a minute, this run takes about 93 seconds.

Type this snippet

Step 1 of 2 in Encore, step 28 of 29 in Language basics.

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Word frequency in other languages

• R