[Rails] nil? vs empty? vs blank? vs present?

Cheatsheet

nil?

• should only be used to check if something is nil or not

• Very commonly used to avoid NoMethodError
• Something like if !record.nil? && record.column == ...

empty?

• should be only be used to check if a string, an array, or a hash is empty or not

blank? vs present?

• Basically they are opposite

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