Hash Methods
Methods available on Ruby Hash objects.
Hash#any?
Check if any, all, or no hash entries satisfy a condition
Hash#dig
Safely retrieve nested values from hashes and arrays without raising errors when keys are missing.
hash.dig(*keys) -> value or nil Hash#each
Iterate over hash key-value pairs with each, each_pair, or each_with_object in Ruby.
hash.each { |key, value| block } -> hash Hash#each_pair
Iterate over hash key-value pairs with each_pair in Ruby, an alias for each.
hash.each_pair { |key, value| block } -> hash Hash#fetch
Returns a value from the hash for the given key, with support for default values and blocks.
Hash#filter
Returns a new hash containing only the key-value pairs for which the block returns a truthy value.
hash.filter { |key, value| block } -> hash Hash#flat_map
Transform hash key-value pairs into arrays. map returns an array of block results; flat_map flattens nested arrays automatically.
hash.map { |key, value| block } -> array Hash#has_key?
Check if a hash contains a specific key
Hash#has_value?
Check if a hash contains a specific value
Hash#invert
Returns a new Ruby hash with keys and values swapped. Duplicate values cause the last key to win.
Hash#keys
Returns an array containing all the keys in a hash.
hash.keys Hash#merge
Merge multiple hashes into a new hash, combining key-value pairs with conflict resolution.
hash.merge(*others) -> hash Hash#reject
Returns a new hash excluding the key-value pairs for which the block returns a truthy value. Use reject! for in-place removal.
hash.reject { |key, value| block } -> hash Hash#select
Returns a new hash containing only the key-value pairs for which the block returns a truthy value. Alias for filter.
hash.select { |key, value| block } -> hash Hash#to_a
Converts a hash to an array of key-value pairs using to_a in Ruby.
hash.to_a Hash#transform_keys
Transform hash keys using a block with transform_keys in Ruby. Available since Ruby 2.5.
hash.transform_keys { |key| block } -> hash Hash#transform_values
Transform hash values using a block with transform_values in Ruby. Available since Ruby 2.5.
hash.transform_values { |value| block } -> hash Hash#value?
Returns true if any value in the hash equals the given object, searching hash values.
hash.value?(value) -> true or false Hash#values
Returns a new array containing all the values in a hash.
hash.values