Ruby クラスごとのメソッド一覧 - Qiita

>String.methods [:try_convert, :allocate, :new, :superclass, :freeze, :===, :==, :<=>, :<, :<=, :>, :>=, :to_s, :inspect, :included_modules, :include?, :name, :ancestors, :instance_methods, :public_instance_methods, :protected_instance_methods, :private_instance_methods, :constants, :const_get, :const_set, :const_defined?, :const_missing, :class_variables, :remove_class_variable, :class_variable_g