CAT 009

CAT-009 — group_by for counters

Severity: info | Confidence: medium | Auto-fix: ❌

Description

group_by for counters — Using group_by + map to count elements allocates many arrays. Use Hash with default value or tally.

Bad code

ary.group_by { |x| x }.map { |k, v| [k, v.size] }

Benchmark

Note

See bench results at bench/cat-009/