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auto_vivification

🌱 Auto‐Vivification for Nested Hashes​

Ruby Hashes don’t auto-vivify nested keys by default. Use Hash.new with a default proc to create missing sub‐hashes on assignment. This simplifies building deep structures without manual checks.

nested = Hash.new { |h, k| h[k] = Hash.new(&h.default_proc) }

nested[:user][:profile][:settings][:theme] = 'dark'
# => { :user => { :profile => { :settings => { :theme => "dark" } } } }

# You can assign arbitrarily deep without initializing intermediate levels.