ENV.index(value) â key Class Public methods Deprecated method that is equivalent

ENV.keep_if { |name, value| } â HashENV.keep_if â Enumerator Class Public methods

ENV.replace(hash) â env Class Public methods Replaces the contents of the environment

ENV.has_value?(value) â true or false Class Public methods Returns true

ENV.each_key { |name| } â HashENV.each_key â Enumerator Class Public methods

ENV.length Class Public methods Returns the number of environment variables

ENV.values_at(name, ...) â Array Class Public methods Returns an array containing

ENV.key?(name) â true or false Class Public methods Returns true

ENV.invert â Hash Class Public methods Returns a new hash created by using

ENV.size Class Public methods Returns the number of environment variables.