Introspection反射机制
# 這個物件有什麼方法
Object.methods
=> ["send", "name", "class_eval", "object_id", "new", "singleton_methods", ...]
# 這個物件有這個方法嗎?
Object.respond_to? :name
=> true
# 這個物件有什麼方法
Object.methods
=> ["send", "name", "class_eval", "object_id", "new", "singleton_methods", ...]
# 這個物件有這個方法嗎?
Object.respond_to? :name
=> true