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Ruby Quicktips

Random Ruby and Rails tips.
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Jan 28 ’10

nil?, empty? and blank?

In Ruby, you check with nil? if an object is nil:

article = nil
article.nil?  # => true

empty? checks if an element - like a string or an array f.e. - is empty:

# Array
[].empty?   #=> true
# String
"".empty?   #=> true

Rails adds the method blank? to the Object class:

An object is blank if it‘s false, empty, or a whitespace string. For example, “”, ” “, nil, [], and {} are blank.

This simplifies

if !address.nil? && !address.empty?

to

if !address.blank?

Documentation: nil?, empty? (String, Array) and blank?

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