Type:
Class

Implements a hash where keys :foo and "foo" are considered to be the same.

rgb = ActiveSupport::HashWithIndifferentAccess.new

rgb[:black] = '#000000'
rgb[:black]  # => '#000000'
rgb['black'] # => '#000000'

rgb['white'] = '#FFFFFF'
rgb[:white]  # => '#FFFFFF'
rgb['white'] # => '#FFFFFF'

Internally symbols are mapped to strings when used as keys in the entire writing interface (calling []=, merge, etc). This mapping belongs to the public interface. For example, given:

hash = ActiveSupport::HashWithIndifferentAccess.new(a: 1)

You are guaranteed that the key is returned as a string:

hash.keys # => ["a"]

Technically other types of keys are accepted:

hash = ActiveSupport::HashWithIndifferentAccess.new(a: 1)
hash[0] = 0
hash # => {"a"=>1, 0=>0}

but this class is intended for use cases where strings or symbols are the expected keys and it is convenient to understand both as the same. For example the params hash in Ruby on Rails.

Note that core extensions define Hash#with_indifferent_access:

rgb = { black: '#000000', white: '#FFFFFF' }.with_indifferent_access

which may be handy.

to_hash

to_hash() Instance Public methods Convert to a regular hash with string keys

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deep_stringify_keys!

deep_stringify_keys!() Instance Public methods

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default

default(key = nil) Instance Public methods

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merge!

merge!(other_hash) Instance Public methods Alias for:

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reverse_merge

reverse_merge(other_hash) Instance Public methods Like merge but

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to_options!

to_options!() Instance Public methods

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[]

[](*args) Class Public methods

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[]=

[]=(key, value) Instance Public methods Assigns a new value to the hash:

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convert_key

convert_key(key) Instance Protected methods

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values_at

values_at(*indices) Instance Public methods Returns an array of the values at

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